Squad boom & talent exodus: Dramatic changes proven in football | OneFootball

How old are professional footballers when they first change clubs? How much larger are club squads compared to earlier times? And how much do clubs rely on their own youth? All intriguing questions that a study by the CIES Football Observatory provides answers to.

The renowned institute conducted a study on the team structures of clubs from the top 30 leagues in Europe. During the investigation period from 2009 to 2025, some surprising developments were observed. 

For example, the squad size of clubs has increased significantly. In 2010, there were an average of 24.44 players, and this number has risen to 26.45 players over the last 15 years. 

(Image source: CIES Football Obs)

Clubs like Chelsea FC or VfL Wolfsburg in the Bundesliga have contributed to this through their personnel planning. 

Additionally, teams are increasingly focusing on height. Somehow, standards need to be defended. Today, players average 183 centimeters in height. In 2010, it was 182.2 centimeters. Not a quantum leap, but quite remarkable given the large number of players. 

(Image source: CIES Football Obs)

The fast-paced nature of football is also felt by coaches, who often face the consequences when a club loses patience after just a few months and lets them go. Erik ten Hag (dismissed after two months at Bayer Leverkusen) or Ange Postecoglu (in charge at Nottingham Forest for only 39 days) know what we're talking about.

There are also constant personnel changes within squads. Between 2010 and 2025, the percentage of players who were with a club for less than a calendar year has significantly increased. Fifteen years ago, it was 41.4 percent. Now, almost half of all squad players are with the team for less than a year. 

(Image source: CIES Football Obs)

A similar trend is seen in the percentage of players who establish themselves outside their home association. At the beginning of the assessment period in 2010, 36.3 percent were considered "expatriate players." Today, the percentage of immigrant players is 47.6 percent. 

(Image source: CIES Football Obs)

In contrast, the percentage of players who make it from their club's youth sector to the professionals has significantly decreased. From 23.1 percent in 2010, the figure has dropped to 15.7 percent. This confirms the assumption that many clubs have increasingly focused on transfers of developed players or top talents who have already taken their first steps at other clubs, rather than relying on their own youth. 

(Image source: CIES Football Obs)

As a result, players decide to change clubs much earlier or are sold by the club for profit. In 2010, the average age of departing players was 22.14 years. 

(Image source: CIES Football Obs)

Currently, players are on average 21.29 years old when they decide to change clubs. It's no secret that younger players tend to fetch higher transfer fees.

What might have previously been just a feeling is now proven: Clubs in the top 5 leagues are recruiting more and younger players, who then often spend less time at the club. The competition for the best players is so fierce that they are being signed earlier and are expected to perform immediately. At least, this is increasingly becoming the norm, as demonstrated by the CIES Football Observatory.

This article was translated into English by Artificial Intelligence. You can read the original version in 🇩🇪 here.

📸 Christian Kaspar-Bartke - 2025 Getty Images