Research from the organization, which represents players worldwide, says some stars are playing almost 80 games in a year, in addition to traveling thousands of miles to play for their international sides.
Tottenham star Heung-Min Son played 78 matches over the last 12 months and traveled nearly 70,000 miles to represent South Korea at the FIFA World Cup, the Asian Games and in the Asian Cup.
“To meet the demands of the match calendar, players are being repeatedly asked to play at their limit, without sufficient rest and recovery,” said Theo van Seggelen, FIFPRO General Secretary.
“This means that they cannot perform at their best and, worse still, that some are struggling with sustained periods of mental and physical strain.
“Scientific research confirms that the health of top players is at risk because of today’s congested match schedule.”
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‘Threshold of human tolerance’
The research found the majority of elite players had, on average, less than the five recommended days between games as a result of the fragmented calendar.
The lack of recovery is associated with a decrease in performance and an increase in the likelihood of injury.
“We need to manage the workload for all players very well and balance the needs between the player, club and country,” said Italy and Juventus star Giorgio Chiellini.
“For us to continuously play at our best and improve performance, we need to be protected from excessive match schedules.”
World governing body FIFA did not immediately respond to CNN Sport’s request for comment.
Sports scientist Simon Brundish told CNN Sport that the congested fixtures list means the sport is “reaching the threshold of human tolerance with the performance load being placed on these players.”
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‘Catastrophic season for injuries’
While welcoming the report as a way of opening the conversation about the physical and mental toll on players, Brundish says the report misses some key statistics.
He says that over the course of the last seven years, the total distance run by players during a game has increased and that the number of sprints performed has risen by a staggering 38%.
He says that last season, the likes of Antoine Griezmann, Luis Suarez and Mohamed Salah all covered more meters and played more minutes than South Korea’s Son, one of the players highlighted in the FIFPRO report.
“Sprinting has the highest metabolic cost on a player so it requires the most recovery,” added Brundish.
“At some point, players are going to start breaking. I think this could be quite a catastrophic season for injuries for the clubs.”
Club’s losing top players
However, Brundish believes that injuries to some of the best players in the world could be the turning point in securing the long-term health of footballers.
He says that last season, the top six teams in the English Premier League — Manchester City, Liverpool, Spurs, Chelsea Arsenal and Manchester United — had between them 42 players at the last week of the World Cup.
These players had fewer than 21 days of pre-season training before the 2018/2019 EPL season started. Brundish says players need at least three weeks off to physically and mentally recover.
“Of those 42 players, 69% missed more than five games, 42% missed more than 10, and 22% missed more than 20 games,” Brundish said.
“Given the quality of player that’s going to the World Cup, you’re missing hugely valuable players for your club. That’s just not sustainable and it’s not going to carry on.”
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Liverpool manager Jurgen Klopp in particular will have to manage his player’s playing time this season, given his team could end up playing a total of 67 games, if they go all the way in every competition, including an incredibly busy festive period.
Liverpool will also compete in December’s FIFA Club World Cup in Qatar — resulting in a 7,000-mile round trip — in addition to a packed domestic schedule.
As a result Klopp’s side may have to play 15 games in 43 days.
If that wasn’t concerning enough, the European Champions are full of international stars who will be traveling thousands of miles to play for their countries.
Goalkeeper Alisson Becker traveled almost 50,000 miles last season, while forward Mane traveled over 60,000 miles.
Mane, who relies heavily on his sprinting, also played in the Africa Cup of Nations throughout the summer while Becker appeared in the Copa America. Mane was still playing for Senegal when Liverpool had already started their pre-season preparations for the 2019/2020 season.
Young players at risk
As the intensity of games increase, professional players at the top of the game are seemingly getting younger and Brundish is concerned that teenagers being exposed to such grueling schedules could have their careers cut short.
Players from the past such as former Liverpool strikers Michael Owen and Robbie Fowler both played a lot of football at a young age but tailed off in their later years.
“You can look at the main body of players and peak years used to be 27, 28 or 29 and they’re now becoming 23, 24, 25,” he said. “Players start to drop off.”