France's World Cup-winning coach Didier Deschamps has criticized the growing workload in top-level football and warned of serious health consequences.
The 57-year-old - who won the tournament as a player in 1998 and coach in 2018 - is leading France into his final tournament in North America, where a record 104 games will take place.
He told Germany's Welt newspaper on Saturday that alarm bells had been ringing for some time. France begin their tournament on Tuesday against Senegal.
"There are 48 teams taking part in the World Cup alone, there are additional competitions like the Club World Cup," he said. "The risk of burn-out therefore cannot be dismissed."
The men's World Cup has been expanded from 32 teams and an extra round of 32 introduced.
The number of games in other competitions such as the Champions League has also increased recently.
Deschamps said recovery periods for players and preparation phases for tournaments were becoming shorter.
"You can now calculate a player's physical fatigue. But what cannot be measured is the player's mental state. And that plays an important role in football," added the former midfielder, who first took charge of Les Bleus in 2012.
