No Pain no Game or More Game More Pain? The Effects of Summer

Congested Games Periods on Professional European Male Football

Players’ Injury Occurrences for the Following Season: A Data

Analytics Approach

Andria Procopiou

and Koulla Parpa

Department of Computing, School of Sciences, University of Central Lancashire (Cyprus), Larnaca, Cyprus

Department of Sports Sciences, School of Sciences, University of Central Lancashire (Cyprus), Larnaca, Cyprus

Keywords:

Football/Soccer Injuries, Injury Risk, Data Analytics, Games Congestion, Fatigue, Sports Trauma, Big Data.

Abstract:

Two recent congested periods, the post Covid19 lockdown period (May-August 2020) and Euro 2020 (June-

July 2021) forced European male footballers to consistently play games for nearly three years with long

duration of congested games and insufﬁcient rest days. This phenomenon has not been previously observed

to such extent. This study uses data analytics and statistics to investigate how these two congested periods

during seasons 19/20, 20/21 and 21/22 affected the injuries occurrences in European male footballers who

both participated in Euro 2020 and played in one of the seven major European leagues, using Transfermarkt

data. The results indicate that the severity and injury days out for each injury were signiﬁcantly increased when

comparing the 20/21 and 21/22 seasons (before and after Euro 2020), but not for 19/20 and 20/21 seasons. In

contrast, there were no signiﬁcant differences on injury rates and occurrences when comparing the congested

games period after March 2020 lockdown with the season before lockdown or the 20/21 season. Furthermore,

the players whose national teams reached the group of 16 stage onwards in Euro 2020, exhibited more ﬁtness-

related occurrences during the 21/22 season. With regards to the injuries each player exhibited, there was a

signiﬁcant difference on their total days out, and days out for their ﬁrst and longest injury when comparing

seasons 20/21 and 21/22. Also, there was a signiﬁcant increase on the severity of injuries each player exhibited

as well as the how soon each player was reported with an injury. However, no similar results were observed

when comparing the 19/20 season (before the Covid19 March 2020 lockdown) and the 20/21 season.

1 INTRODUCTION

The increase of games and competitions in Euro-

pean male football has led to even more congested

ﬁxture periods during each calendar year, starting

with the introduction of the Nation’s League back

in 2018. This matter was magniﬁed after the ﬁrst

Covid19 pandemic lockdown, in March 2020. The

European leagues were interrupted, only to resume

in May 2020, along with the European club com-

petitions (UEFA Champion’s League, UEFA Europa

League) and ﬁnish around mid-August 2020 with the

two European Competitions ﬁnishing towards the end

of August. From the seven most successful European

leagues according to the UEFA coefﬁcient (UEFA,

2023) (Premier League, La Liga, Bundesliga, Ligue

1, Serie A, Eredivise and Primeira Liga), we observe

that Ligue 1 and Eredivisie did not complete their re-

maining ﬁxtures. The Premier League with 10 games

remaining, Bundesliga with 9 games remaining and

Serie A with 12 games remaining were completed

in the time-span of approximately 40 days. The La

Liga 11 remaining games were conducted in approx-

imately 36 days and the Primeira Liga 10 remaining

games in 51 days. We also note that selected teams

from this set of European leagues played additional

games in both domestic and European competitions.

Undoubtedly, this issue contributed to the in-

creased congested games period. Provided that many

of the teams returning back into play also had to com-

pete in other domestic competitions as well as interna-

tional ones, they had to face a challenging congested

games period ahead. In practice, this yielded at least

1.75 games per week for the Premier League teams,

2.1 games for the Serie A teams, 1.57 games for the

Bundesliga teams, 2.14 games for the La Liga teams,

202

Procopiou, A. and Parpa, K.

No Pain no Game or More Game More Pain? The Effects of Summer Congested Games Periods on Professional European Male Football Players’ Injury Occurrences for the Following

Season: A Data Analytics Approach.

DOI: 10.5220/0012233600003587

In Proceedings of the 11th International Conference on Sport Sciences Research and Technology Support (icSPORTS 2023), pages 202-212

ISBN: 978-989-758-673-6; ISSN: 2184-3201

and 1.37 for the Primeira Liga teams. Less than a

month later, 20/21 football season commenced, giv-

ing little to no sufﬁcient time to the male footballers

to recover properly. All the seven major European

leagues ﬁnished mid-end of May, with the Euro 2020

competition only starting in at 11/6/2021. The con-

duction of a back-to-back nearly full summer of foot-

ball games has left the majority of male European

football players with, once again, insufﬁcient time to

rest, properly recover, and appropriately participate in

the pre-season training sessions (Julian et al., 2021).

1.1 Motivation and Contribution

The literature consists of notable studies investigating

congested games periods, including seasons interrup-

tions (e.g. winter break) (Leventer et al., 2019), pre-

training seasons (Ekstrand et al., 2020), congested

schedules (Dupont et al., 2010b), (Lago-Pe

nas et al.,

2011), (Dellal et al., 2015), (Julian et al., 2021),

(Trewin et al., 2017) and so on. However, this 3-

year period with such a long duration of congested

games and insufﬁcient rest days between seasons has

not been previously observed and what it could mean

for the players’ ﬁtness, health and overall well-being.

In this study we aim to investigate on whether

and how this 3-year period (seasons 19/20, 20/21 and

21/22) has affected the injury occurrence and rates

in male European footballers, competing in both one

of the seven most difﬁcult European leagues accord-

ing to the UEFA coefﬁcient (UEFA, 2023) and Euro

2020. In summary, this period was special for the fol-

lowing reasons:

1. Season 19/20 was interrupted for approximately

40 days in each country, only for the players to

return back and complete the season in approxi-

mately 40 days.

2. Season 20/21 started in less than a month later on,

giving insufﬁcient time for the players to rest, re-

cover and receive proper pre-training. This was

more evident for the players who also participated

in the international competitions (e.g. Champi-

ons’ League/Europa League). In addition, to the

already congested programme experienced so far,

the Euro 2020 competition was held during sum-

mer 2021.

Hence, we are interested in following research

questions:

1. RQ1: Has the Euro2020 competition increased

the overall number of injuries for the following

season?

2. RQ2:Has the congested games period after

Covid19 lockdown (March 2020) increased the

overall number of injuries for the remaining of the

season (summer 2020) or season 20/21?

3. RQ3: Have these two congested games periods

(Remaining of 19/20 season after March 2020

lockdown and Euro 2020 held in summer 2021)

increased fatigue and ﬁtness related occurrences

for the respective following season?

4. RQ4: Has the Euro2020 congested period af-

fected the injuries per player for the following sea-

son?

The rest of the paper is organised as follows; in

Section 2, we review the relevant literature. Proceed-

ing, we investigate the Research Questions using the

data extracted from Transfermarkt and discuss the re-

sults. Then, we dicuss the paper’s limitations and fu-

ture work. Finally, we make our concluding remarks.

To the best of our knowledge, no other study at-

tempted to perform such in-depth investigation of in-

juries related to European male football players from

seven European major leagues for three consecutive

seasons (19/20, 20/21 and 21/22) which consisted of

two summer congested games periods in-between. In

addition, no other study attempted to investigate how

each of these two games congested periods affected

the injury occurrence and/or rates for the following

season. Our work is summarised through the follow-

ing contributions:

1. Total Injuries Dataset: Construction of a dataset

of all the injuries of male footballers who partic-

ipated in Euro 2020 and played for a club from

one of the seven European leagues with the high-

est UEFA coefﬁcient and their labelling based on

their severity and category according to (Del Coso

et al., 2018) using the Transfermarkt platform for

seasons 19/20, 20/21 and 21/22.

2. Injuries per Player Dataset: Construction of a

dataset of injuries for each player with the calcula-

tion of various metrics based on their total number

of injuries, ﬁrst and longest injury for each of the

three seasons.

3. Data analysis of injuries reported for 340 different

male footballers using both datasets explained in

1) and 2).

2 REVIEW OF THE LITERATURE

It is estimated that footballers can be exposed

from 10-20 consecutive weeks of congested games,

both domestically and internationally (transfermarkt,

2023) in a single season. Inevitably, this leads to play-

ers having fewer days between games, thus unable

No Pain no Game or More Game More Pain? The Effects of Summer Congested Games Periods on Professional European Male Football

Players’ Injury Occurrences for the Following Season: A Data Analytics Approach

203

to rest and recover properly (N

elec et al., 2012),

(Ispirlidis et al., 2008), (Bengtsson et al., 2013a).

There are different studies proving the link be-

tween congested games periods and injury incidence

rates. Carling et al. (Carling et al., 2016) investigated

injuries in short periods of games congestion in 25

players who participated in the French Ligue 1 and

European competitions over seasons 2009-2015. The

authors monitored the exposure time and reported in-

juries during congestion periods and non-congestion

periods. The results demonstrated a higher risk of in-

jury during the ﬁnal 15 minutes of the second game

of a congested period, in contrast to the respective

non-congested periods. Also, they reported an over-

all higher risk of injury, a risk of ankle sprains and

non-contact injuries during the ﬁnal game of a three-

match congestion period in contrast to the respective

time-frame of a non-congested period.

Similarly, Bengtsson et al. (Bengtsson et al.,

2013a), also aimed to investigate how congested game

periods affected 27 teams over 11 seasons. Linear

regression was used to investigate on whether there

was an association between the recovery time, game

load, injury rates and performance from each team.

They reported an association between games lost and

short recovery time in Europa League. They also re-

ported an increased rate of injury and muscle injury

(hamstring and quadriceps), when there was a game

in equal or less than 4 days, compared to 6 days.

There was also an increase in ligament injuries during

the training session after the congested games period.

Similarly, the authors in (Dupont et al., 2010a) moni-

tored 32 football players from a team participating in

the Champions League to investigate the possible ef-

fects a 2 weekly game congestion period for 52 home

games had for their performance over a 2-season pe-

riod. Injury rate was signiﬁcantly increased during the

congestion game period compared to non-congestion

period (1 weekly game).

Aiming to investigate how congested game pe-

riods affect both performance and injury rate, Del-

lal et al. (Dellal et al., 2015) monitored 16 players

competing in the French League, French Cup and the

Champions’ League. The period monitored was dur-

ing the 2011-2012 season’s three different congested

periods of games (=six games in 18 days). In their

results, they report no signiﬁcant differences in any

of the six games during the congested period or in-

between congested games periods when it came to

the players’ physical and technical performance. Fur-

thermore, even though there was also no change in

the total incidence of injuries, the injury rate during

game-play was signiﬁcantly higher during the con-

gestion period. On the other hand, the mean lay-off

duration for injuries was signiﬁcantly shorter during

congested periods than in non-congestion periods.

Multiple studies aimed to investigate a poten-

tial differentiation in physical game performance and

injury rates and occurrences before and after the

Covid19 March 2020 lockdown in different European

football leagues, including Bundesliga and Serie A

(Thron et al., 2021), (Krutsch et al., 2022), (Marotta

et al., 2022a). In their ﬁndings they report that there

were no signiﬁcant differences with regards to the in-

jury rates and occurrences before and after the ﬁrst

lockdown. Thron et al. (Thron et al., 2022) rightfully

claim that the increase in substitutions from 3 to 5

has a positive effect in reducing the injury risk. Sim-

ilarly, a study conducted for the Japanese league was

also unable to prove a signiﬁcant increase on injury

occurrences before and after the March 2020 lock-

down (Matsunaga et al., 2023). However, the authors

report that muscle-related injuries were notably in-

creased during the ﬁrst two months after the initial

suspension period.

From the studies presented, injury incidence was

higher during congested periods, but not after the

Covid19 March 2020 lockdown. This is of special

interest since it directly contradicts previous ﬁndings

proving a notable increase on injury occurrences af-

ter short breaks (e.g. winter break) (Leventer et al.,

2019), (Ekstrand et al., 2020). A notable difference

between a normal congested games period (which in-

volves international games) compared to the Covid19

lockdown after season, was travelling to and from

away matches (Fowler et al., 2015), (Abbott et al.,

2018) or/and playing during the night (Fullagar et al.,

2016). This could potentially play a potential roles

in the players being exposed to injury risk, something

which holds especially true for the Euro 2020 compe-

tition with all the excessive travelling conducted.

However, the fact remains that these two con-

gested games periods occurred in two-consecutive

summers, in 2020 and 2021. To the best of our knowl-

edge, there has been no previous work conducted in-

vestigating the effects of both these two congested

games period across such a large number of male

footballers who player across seven different Euro-

pean leagues. Most importantly, to the best of our

knowledge, there has been no other study investigat-

ing how these two congested games periods could

have impacted the injury rates and occurrences for the

following season. Our study aims to ﬁll in these gaps

and investigate the possible effects on injury rates and

occurrences due to this back-to-back summer games

congested period for the next seasons respectively.

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204

3 METHODS

3.1 Experimental Testbed

Implementation

For the extraction/analysis and visualisation of the

data, Python 3.8, Pandas, Seaborn and Selenium li-

braries were used. All the data our implemented

software scrapped through, was from Transfermarkt

(transfermarkt, 2023). Only the players who partic-

ipated in Euro 2020 and belonged to a team of the

seven following football leagues presented in the In-

troduction section were considered.

3.2 Injuries Classiﬁcation and Data

Collection

Unfortunately, footballers can suffer from a plethora

of different injuries due to the high physical demands

and the high risk of physical impact of the sport.

There are various types of injuries and with differ-

ent severity. Injury severity describes the severity of

an injury based on how many days each individual

was out. Hence, we followed the injuries classiﬁca-

tion method proposed by (Del Coso et al., 2018). In

total, there are four different classiﬁcations, presented

below: Minor injuries which lasted less than 7 days;

Mild injuries which lasted 7-13 days; Moderate in-

juries which lasted 14-20 days; Severe injuries which

lasted more than 20 days. Based on this information,

we classiﬁed each injury based on its severity, as pre-

viously described.

Using (Del Coso et al., 2018), we classiﬁed each

injury based on the description by Transfermarkt. We

brieﬂy explain how the type of an injury is conducted

based on the authors’ proposed model. Bone-related

injuries include fractures and other-bone related in-

juries. Joint and/or ligament injuries include dislo-

cations/subluxations, ligament stretching, tear or rup-

ture, meniscus/cartilage wearings, tears or ruptures

and so on. Muscle and/or tendon injuries include

muscle cramps, tears or ruptures, tendon injuries and

so on. Contusions injuries include hematomas, abra-

sions or lacerations. Nervous system injuries in-

clude concussions and other nervous-related injuries.

Knocks include all types of knocks.

Table 1: Euro 2020 Players by Country.

Country Players No.

Austria 20

Belgium 20

Croatia 12

Czech Republic 9

Denmark 17

England 24

Finland 3

France 26

Germany 26

Hungary 4

Italy 26

Netherlands 22

North Macedonia 3

Poland 11

Portugal 26

Russia 3

Scotland 9

Slovakia 8

Spain 24

Sweden 8

Switzerland 16

Turkey 11

Ukraine 3

Wales 9

3.3 Data Collection and Dataset

Construction

3.3.1 Injuries Dataset Construction

It was important to ﬁrstly collect all the necessary in-

formation for the players who participated in Euro

2020. We obtained the full lists of the squads par-

ticipating from (UEFA, 2021) . Then, we picked up

the players who participated in one of the seven Eu-

ropean leagues considered, namely Premier League,

La Liga, Bundesliga, Ligue 1, Serie A, Eredivisie and

Primeira Liga. The total number of players consid-

ered for the present study was 340. Only the players

who both participated in Euro 2020 and belonged to

one of the seven European leagues stated in the Intro-

duction were considered and summarised in Table 1.

The general information we extracted for each player

was the following: player’s name, player’s age (at the

start of the season), player’s position, player’s club,

player’s league and player’s birth country. For the

purpose of the study, we extracted injury information

for the set of player explained above for three con-

secutive seasons, speciﬁcally 19/20, 20/21 and 21/22

seasons. The total number of injuries per season is

presented in Table 2. All non-injury related reasons

for absence (e.g. due to illness) records have been

omitted. For each injury occurred to each player, the

following information was extracted:

No Pain no Game or More Game More Pain? The Effects of Summer Congested Games Periods on Professional European Male Football

Players’ Injury Occurrences for the Following Season: A Data Analytics Approach

205

Table 2: Total Injuries and Fitness Occurrences per Season.

Season Injuries No.

19/20 (before/after March Lockdown) 455(377/78)

20/21 449

21/22 498

• Injury Season: Season the injury occurred.

• Injury Description: Injury Description the Trans-

fermarkt platform provided.

• Injury Start Date: Date the injury occurred.

• Injury Start Month: Month the injury occurred.

• Injury End Date: Date returned from injury.

• Injury Days Out: The total number of days the

player was out due to injury.

• Injury Severity: Based on the days injured, the

classiﬁcation of the injury’s severity.

• Injury Type: Type of the injury based on the ”In-

jury Description” ﬁeld.

3.3.2 Injuries per Player Dataset Construction

For the purpose of this study, it is equally impor-

tant to investigate on how the different injuries occur

not only in overall, but also on each player individ-

ually. Proceeding, we calculated the relevant infor-

mation for each player’s injury history. Speciﬁcally,

the information extracted for each player per season

included:

• Injuries Total Number: Total number of injuries a

player had for the season.

• Injury Total Days Out: Total number of days the

player was out due to injuries for the season.

• Injury Maximum Days Out: Number of days

the injury from which the player recovered the

longest lasted.

• Injury Maximum Severity: Severity the injury

from which the player recovered the longest.

• Injury Maximum Category: Category the injury

from which the player recovered the longest.

• Injury Maximum Month: Month the injury from

which the player recovered the longest occurred.

• Injury First Days Out: number of days the player

had their ﬁrst injury for the season lasted.

• Injury First Severity: Severity the player had their

ﬁrst injury for the season.

• Injury First Category: Category the player had

their ﬁrst injury for the season.

• Injury First Month: Month the player had their

ﬁrst injury for the season.

4 RESULTS AND DISCUSSION

For the analysis of the results and the investigation

of the research questions deﬁned in the Introduction

presented in this paper, the following techniques were

used:

• Descriptive Analytics and Statistics (mean, stan-

dard deviation, median, mode, min, max and quar-

tiles) to calculate, describe, and summarise col-

lected injury data, including rates per season, days

out, severity, and start date.

• Inferential Statistics and Diagnostic Analytics

(Mann Whitney U test) to investigate signiﬁcance

on the difference between the injury days out

• Bar Charts, Pie Charts and Tables to visualise the

data extracted.

4.1 RQ1: Has the Euro2020

Competition Increased the Overall

Number of Injuries for the

Following Season?

Based on the injuries for the two seasons presented

in Table 2, we observe an increase of 10.9% (3 s.f.).

Hence, we cannot support that the conduction of ad-

ditional congested games through Euro2020 signiﬁ-

cantly increased the total number of injuries occurred.

However, it appears that the conduction of Euro2020

signiﬁcantly increased the number of injury days out

for each injury. Based on Table 3, the mean/median

values for the injury days during the 20/21 season

were 19.95 and 12 respectively while for the 21/22

season 28.22 and 15. Also, there is a notable dif-

ference between the values for the maximum injury

days variable between the two seasons. By perform-

ing Mann-Whitney U test, we conclude that there is

a signiﬁcant difference between the injury days out

between the two seasons (p=0.0001). We proceed by

analysing in further the injuries for both seasons, fo-

cusing on the distribution of the severe and moderate

type injuries as well as the types of injuries observed

for the two seasons.

For the 20/21 season, 127 severe injuries were re-

ported, while for the 21/22, 185, exhibiting a 45.67%

Table 3: RQ1 Descriptive Statistics.

Season

Mean

(St.Dev)

Mdn. Md.

Min/

Max

Quartiles

20/21

19.95

(24.99)

12 7 1/242

6 (25%)

25 (75%)

21/22

28.22

(41.38)

15 7 1/383

7(25%)

31.5 (75%)

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206

increase. With regards to the moderate injuries, for

the 20/21 season 49 were reported and for the 21/22

season, 64, exhibiting a 30.61% increase. In addition

to the signiﬁcant difference in the number of severe

and moderate injuries, we also observe that such a no-

table difference is also observed on the injury out days

variable for the severe and moderate types of injuries.

Speciﬁcally, the mean/median of injury out days for

the severe injuries during the 21/22 season were 56.9

(3 s.f.) and 36 respectively, while for the 20/21 sea-

son they were 45.6 (3 s.f.) and 34. For the moderate

injuries, the mean/median of injury days during the

21/22 season were 18.4 (3 s.f.) and 18 respectively,

while for the 20/21 season they were 18.3 (3 s.f.) and

18. Based on the results presented, we believe that the

conduction of the Euro2020 competition had an im-

pact not only on how many days an injury lasted for

the players who participated in, but also on how many

severe and moderate types of injuries, as well as for

the former’s overall number of injury days out for the

severe injuries. Based on Figure 1 results, we observe

that in both seasons, the distribution of injuries based

on their type remained unchanged. As expected, the

muscle and tendon injuries were the most frequent

amongst the players investigated, followed by joint

and ligament injuries. The rest of the injury categories

did not demonstrate any signiﬁcant differences. Even

though we do not have sufﬁcient information on the

nature of the injury and whether it was caused due to

overuse, it is clear that there is a signiﬁcant rise in the

overall numbers of muscle/tendon and joint/ligament

injuries when comparing the 20/21 and 21/22 seasons.

In addition, based on the results in Figure 2, we

observe that the Italian players had the highest num-

ber of injuries total for both seasons 20/21 and 21/22.

This is possibly the case due to two reasons. Firstly,

the Italian national team reached the ﬁnal of Euro

2020 and eventually won the trophy. This indicates

that the Italian players eventually played more games

and the longest with little break between them dur-

ing the competition and had less time to rest before

the start of the pre-season training. Secondly, the ma-

jority of Italian players belong to the Serie A league,

where during the rest of the 19/20 season, the Ital-

ian teams played at least 2.1 games per week. A full

congested-games period (summer 2020), followed by

a full season and the, undoubtedly, overperformance a

team requires to win a European competition is likely

to have contributed to the high injury occurrences for

the Italian players.

Figure 1: Injuries Categories Distribution for 20/21 and

21/22 Seasons.

Table 4: RQ2 Season 19/20 Injury rates per League.

Season

Premier

League

Bundes

-liga

Liga

Serie

Primeira

Liga

19/20

Phase A

3.65 2.64 1.86 1.07 0.29

19/20

Phase B

1.79 1.24 1.03 0.48 0.07

4.2 RQ2: Has the Congested Games

Period after Covid19 Lockdown

(March 2020) Increased the Overall

Number of Injuries for the

Remaining of the Season (Summer

2020) or Season 20/21?

For the purpose of this research question, we decided

not to include the records of injuries from the two

fully interrupted leagues during the 19/20 season due

to Covid19 (Ligue 1 in France and Eredivisie in the

Netherlands). For the remaining of this subsection,

we refer to the 19/20 season until March 2020 as Sea-

son 19/20 Phase A (lasted for 34.5 weeks) and from

April 2020 to August 2020, as Season 19/20 Phase B

(lasted for 14.5 weeks). In Table 4, the weekly injury

rates per league for season 19/20 Phases A and B. By

performing a Mann-Whitney U test on the injury rates

between the two phase, we conclude that there are no

signiﬁcant differences between the two distributions

(p=0.2113). Therefore, there are no signiﬁcant dif-

ferences on the injury rates between the two phases

and no changes between the injury rates between the

leagues. Our ﬁndings are consisted with the related

studies presented in the Review of the Literature sec-

tion.

To ensure consistency when comparing the 19/20

season (Phase A) and the 20/21 season, we only con-

sidered the injuries from the start of each season until

No Pain no Game or More Game More Pain? The Effects of Summer Congested Games Periods on Professional European Male Football

Players’ Injury Occurrences for the Following Season: A Data Analytics Approach

207

Figure 2: Total Injuries per Country for 20/21 and 21/22 Seasons.

March 2021. The total number of injuries reported

during the 19/20-Phase A season was 313, while for

the 20/21 season was 343. Based on the results ob-

tained, we observe an 9.58% increase in the over-

all number of injuries. Regarding the injury days

out variable, Table 5, we observe that interestingly,

the average days out value for the 19/20 season is

29.73 (±39.26) days, while for the 20/21 season was

19.10(±21.07) days. By performing a Mann-Whitney

U test, there is a signiﬁcant difference (p=0.00164).

Hence, we conclude that the injuries did not exhibit

any increase rates of injury out days due to Covid19

after the ﬁrst-lockdown congested period.

4.3 RQ3:Have These Two Congested

Games Periods Increased Fatigue

and Fitness Related Occurrences for

the Following Season Respectively?

Based on the literature, we assume that in a season

following a congested period of games, more ﬁtness-

related occurrences will be observed. The occur-

rences we consider as ﬁtness-related ones are reported

by Transfermarkt as ”Fitness”, ”Muscle Fatigue”, and

”Rest”. Hence, we made two comparisons:

• Comparison No.1: Comparison between the play-

ers who participated in the Euro 2020 competition

for seasons 20/21 (before Euro2020) and 21/22

(after Euro2020).

• Comparison No.2: Comparison between the play-

Figure 3: Fitness-related Occurrences by Country for Sea-

son 20/21.

ers whose leagues were not fully interrupted af-

ter the ﬁrst Covid19 lockdown, speciﬁcally season

19/20 (until March 2020) and season 20/21.

4.3.1 Comparison No. 1 Results

To gain a more accurate view of the injuries’ occur-

rences we considered only the injuries until March

2021. With regards to the total number of ﬁtness-

related occurrences, there is no signiﬁcant difference

between the two seasons, 30 for 20/21 and 28 for

21/22. By performing a Mann-Whitney U test, we

observe that there is no signiﬁcant difference between

the distributions of the injury days out for the two sea-

sons (p = 0.448). Therefore, we conclude that there is

no signiﬁcant increase in the number of injury days

out for each injury occurrence from one season to

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Table 5: RQ3 Descriptive Statistics - Comparison No.2.

Season

Mean

(St.Dev)

Mdn. Md.

Min/

Max

Quartiles

19/20

30.3

(40.7)

15 7 0/263

7(25%)

33(75%)

20/21

18.9

(23.5)

11 7 0/242

6(25%)

23(75%)

Figure 4: Fitness-related Occurrences by Country for Sea-

son 21/22.

the other. However, based on Figures 3 and 4, we

note that for the 21/22 season, more than 50% of the

ﬁtness-related occurrences were observed on players

whose national teams reached the quarter-ﬁnal stage

of the Euro2020 competition. From the remaining

50%, only 3.5% of ﬁtness-related occurrences hap-

pened to players whose teams did not pass through

the group stages phase of the Euro2020 competition,

with the remaining 46.5% occurring to players whose

national teams reached the group of 16 stage. In con-

trast, for the 20/21 season, the ﬁtness-related occur-

rences of players whose national teams would reach

the quarter ﬁnals stage was only 20%.

In addition, the parentage of the moderate and se-

vere ﬁtness-related occurrences the 21/22 season was

21.4% (3 s.f.) while for the 20/21 season was 13.3%

(3 s.f.). Concluding, the congested games period of

Euro2020 competition seems to not have signiﬁcantly

increased the number of ﬁtness-related occurrences or

their days out. However, it potentially had an im-

pact on which players experienced such occrrrences

based on how far they went through the competition,

given that Italy (Euro2020 champions) demonstrated

the most ﬁtness-related problems.

4.3.2 Comparison No.2 Results

For the second comparison, the results are presented

in Table 5. Firstly, in contrast to the previous com-

parison, we observe that for the 19/20 season (until

March 2020) the total number of ﬁtness-related oc-

currences was only half the total number, compared

Figure 5: First Injury Severity for 20/21 and 21/22 Seasons.

Figure 6: First Injury Month Occurrence for 20/21 and

21/22 Seasons.

to the 20/21 season (until March 2021) , speciﬁcally

12 and 25, yielding an increase of 108.33%. However,

we observe that during the 19/20 season, the days out

between the two seasons was not signiﬁcantly dif-

ferent by using a Mann-Whitney U test(p=0.4965).

Based on the two sets of results presented, the con-

gested games period after the Covid19 pandemic ﬁrst

lockdown (March 2020) possibly affected the ﬁtness-

related occurrences, compared to the 19/20 season,

but it did not signiﬁcantly affect the days out for each

ﬁtness occurrence reported.

4.4 RQ4: Has the Euro2020 Congested

Period Affected the Injuries per

Player for the Following Season?

A possible increase in the total number of injuries,

when comparing two or more seasons does not nec-

essarily mean that all the of the players considered

exhibited a higher number of injuries personally. A

plausible scenario would consist of certain players

who are more injury prone, due to various reasons,

injured more frequently. Therefore, it was essential

to investigate on whether the conduction of Euro2020

or the Covid19 March 2020 lockdown had a negative

impact on the injuries occurrence for each individual

player. Hence, we aimed to investigate on how the

injuries, were classiﬁed based on the severity system

chosen in Section 3.2, as well as what month each in-

No Pain no Game or More Game More Pain? The Effects of Summer Congested Games Periods on Professional European Male Football

Players’ Injury Occurrences for the Following Season: A Data Analytics Approach

209

Table 6: Injuries for Seasons 20/21 and 21/22.

Season Players No. Mean (Stand. Dev.)

20/21 225 1.99(1.15)

21/22 233 2.13(1.43 )

jury for every individual player was reported.

In Table 6 we summarise the total number of in-

jured players and the mean and standard deviation of

injuries per player for seasons 20/21 and 21/22. In

general, based on the results in Table 6, the total num-

ber of players injured between the 20/21 and 21/22

seasons was increased by only 4%, In addition, the

mean(stand.dev.) number of injuries per player for

the 20/21 and 21/22 seasons was 1.99(1.15) and 2.13

(1.43) respectively and their difference cannot be con-

sidered signiﬁcant (p=0.881). The mean number of

injuries each player suffered from during both seasons

results agree with previous studies (Ekstrand et al.,

2011). Hence, we conclude that the number of injured

players and the total number of injuries per player was

not signiﬁcantly altered in seasons 20/21 and 21/22.

However, based on the results presented in Ta-

ble 7, we observe that there is a signiﬁcant differ-

ence on the injury days out the players have experi-

enced between the two seasons. Speciﬁcally, there

is a signiﬁcant difference in the total days out vari-

able (p=0.0002), the ﬁrst injury days out variable

(p=0.00308), and the maximum injury days out vari-

able (p=00308). Hence, it is evident that a player has

spent signiﬁcantly more time being out due for all of

their injuries, for their ﬁrst injury as well as for their

maximum days out injury.

Furthermore, with regards to the ﬁrst injury each

player has experienced when comparing the seasons

20/21 and 21/22, we ﬁrstly observe that the total num-

bers of severe and moderate injuries has been con-

siderably increased, as illustrated in Figure5. There-

fore, we believe that the conduction of Euro2020 has

contributed not only on earlier injuries during the

season, but also on more serious injuries being re-

ported. In addition, the number of injuries for July,

August, March, April, May and June was signiﬁ-

cantly increased, when comparing the two seasons,

based on Figure 6. This is due to the players com-

ing back to full-training almost immediately, follow-

ing the Euro2020 competition, hence why during the

ﬁrst two months (July and August), a considerable in-

crease in injuries was observed. Regarding the rest

of the months (March, April, May and June), we be-

lieve this is due to the overplaying from the players

due to the high number of games to play with insuf-

ﬁcient resting periods between them, followed by the

conduction of Euro2020.

Table 7: Injuries Mean and Stand.Dev for Seasons 20/21

and 21/22.

Season Days Out 1st Injury Max Injury

20/21 38.04(36.86) 21.41(29.59) 28.24(30.83)

21/22 57.95(60.87) 29.93(43.77) 43.86(53.49)

Figure 7: Maximum Days Injury Severity for 20/21 and

21/22 Seasons.

In Figures 8 and 7, the injuries that kept the play-

ers out of game for the maximum amount of time dur-

ing the seasons and their severity classiﬁcation are

presented respectively. Evidently, there is a signif-

icant difference on the maximum days out injuries

during August and September for season 21/22 com-

pared to season 20/21. We believe this is once again

to the congested games of Euro2020, since these in-

juries occur soon after the end of the competition. We

also observe a considerable increase on the maximum

days out injuries during April and May. We believe

the same case applies as for the ﬁrst injuries results al-

ready described. In addition, we observe that there is

a considerable increase on the maximum days out in-

juries injuries which were of severe type for the 21/22

season, compared to the 20/21 season, with approxi-

mately 15 days of an increase. Hence, we conclude

that Euro2020 has affected the maximum days out in-

juries both from an month occurrence but also from a

severity point of view.

Figure 8: Maximum Days Injury Month Occurrence for

20/21 and 21/22 Seasons.

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4.5 Limitations and Future Work

Unfortunately, injuries records are not always ac-

curate and reliable, including the records from the

Transfermarkt platform. However, as authors in

(Thron et al., 2022) have effectively pointed out, in-

jury surveillance can be inconsistent and can nega-

tively impact the data. However, notable studies used

it (Grassi et al., 2020), (Niederer et al., 2018),(Man-

nino et al., 2023), (Marotta et al., 2022b) for injuries

reporting, so we believe it is a reliable source for play-

ers who compete in major European leagues. Future

work could include collecting data for male football

players who did not participate in Euro 2020 but went

through the congested games period after the Covid19

March 2020 lockdown to investigate in further depth

if the competition had a greater inﬂuence on injury

rates of players competing in one of the seven ma-

jor European leagues. In addition, since Copa Amer-

ica was conducted around the same time, it would

be interesting to investigate on whether players who

competed in this competition were injured differently.

A more in-depth study on what factors could affect

the injury rates of players. In that way, intelligent

techniques such as A.I. and machine learning could

be adopted for possible predictions on how much a

player is at risk of being injured.

5 CONCLUDING REMARKS

Undeniably, players’ availability can be proven piv-

otal for a team’s success over a season (Eirale et al.,

2013), (Bengtsson et al., 2013b). Injuries in profes-

sional football can be proven costly for clubs (Ek-

strand, 2013). It is essential for injury risk to be

signiﬁcantly minimised. Unfortunately, with the in-

crease of congested games periods this has become

a considerable challenge. This study was conducted

to investigate on whether two speciﬁc summer con-

gested game periods (Covid19 congested games in

summer 2020 and Euro 2020 in summer 2021) af-

fected the European players’ injury rates and occur-

rences, injury days out period and severity.

From the results obtained, we observed that the

severity and injury days out for each injury were sig-

niﬁcantly increased from the 20/21 to the 21/22 sea-

son. In contrast, there were no signiﬁcant differ-

ences on either the injury rates or occurrences when

comparing the congested games period after Covid19

March 2020 lockdown with the season before the

lockdown. Furthermore, the Euro2020 competition is

likely to have played a role in players who reached the

stage of 16 onwards and exhibited increased ﬁtness-

related problems the following season. This was

mostly evident in Italian players who won the compe-

tition. Although the injuries per player were not sig-

niﬁcantly increased, the injury total days out each of

them had was signiﬁcantly increased. Similarly, the

ﬁrst injury each player has endured has signiﬁcantly

lasted longer than the 20/21 season. This was also the

case for the injury each player needed the longest to

recover from. In addition, it was evident that both the

ﬁrst injury and the maximum in days out injury each

player has exhibited occurred signiﬁcantly sooner the

the 20/21 season. Finally, we observed a signiﬁcant

increase on the severity of injuries each player has ex-

hibited. Hence, we believe that these two congested

games periods had a negative effect on the players’ in-

jury rates and injury days out, as well as their severity.

Concluding, we believe a more appropriate manage-

ment of the workload of players should be considered,

so not only injuries can be avoided but also minimise

the risk for serious injuries that can be season ending

for the players.

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