Julian Alvarez was picked in 83 match-day squads last season. Darwin Nunez, Luis Diaz and Phil Foden played in 72 games. Cristian Romero travelled more than 160,000 kilometres for international games.

In comparison, Erling Haaland had a summer break without a national-team tournament and has started the season fresh with a flurry of goals for Manchester City.

The physical and psychological demands on elite footballers last season were detailed on Thursday by their global union FIFPRO, which is challenging governing body Fifa in two legal cases.

FIFPRO published its annual Player Workload Monitoring report that surveyed about 1,500 players. It aims to back legal arguments that too much is being asked of the union's members without proper consultation about constant expansion of international competitions.

“This season will be the defining season,” FIFPRO board member Maheta Molango said of a congested 2024-25 calendar that ends with the first 32-team Club World Cup, organised by Fifa in the United States.

A FIFPRO online briefing about the report included officials from player unions in England and France who filed a claim against Fifa in June at the Brussels Court of Commerce. It seeks a referral to the European Court of Justice in Luxemburg, which ruled last year on the Super League case.

In a separate legal case, FIFPRO's European division is teaming up with domestic leagues to file a complaint at the European Commission in Brussels against how Fifa decides to expand its competitions, including the first 48-team men's World Cup in 2026.

“The gap between those who schedule complex international competitions and those who play and experience them has never been bigger,” FIFPRO policy director Alexander Bielefeld said.

The union has targeted Fifa and not European football body Uefa, which also has added more games starting this season to the Champions League and Europa League.

“Lots of people tell us, Why don't you also attack Uefa?'” French union official David Terrier acknowledged. “The difference is we have had discussions with Uefa. There is a will to find solutions together. That hasn't been the case with Fifa.”

The new Club World Cup, which will be played every four years, was a tipping point for the expansion of international competitions, the union said.

Fifa's consistent defence that national team games account for a small fraction of total games compared to club football was “a misleading perspective,” the union said.

The latest player workload report switches focus from the numbers of games and minutes actually played toward time spent on work duty. This included selection in match-day squads and for national team training camps which added the same stresses on travel and preparing for games, the union said.

Players who went to the 2024 European Championship spent 17 per cent of their working time last season with national teams, the report suggested, adding those players had as little as 42 days rest and recovery over the year.

Haaland did not play at Euro 2024 because Norway did not qualify, noted Molango, CEO of the players' union in England, and was fully rested to start the Premier League. He has seven goals in three games for Manchester City.

“Now you see the result. He is back to being the machine that we saw when he first joined,” Molango said.

He also highlighted Mohamed Salah's fast start at Liverpool after playing no offseason tournament with Egypt.

The report also compared Real Madrid star Jude Bellingham playing many more games at the same age — 21 — than Wayne Rooney, a previous teenage star for England.

“There are no safeguards,” FIFPRO researcher Darren Burgess. “The science tells us that these athletes are still growing and we are putting them under more and more load which generally leads to injury.”