The findings have been revealed in a report by FIFPRO, the worldwide representative organisation for 65,000 professional footballers, which highlights risks of injury to players as a result.

With the event being staged, unusually, in the middle of the European season in order to avoid Qatar's summer heat, pressure has been put on many national leagues to pack in more matches.

The report, entitled The Player Workload Journey, shows Portugal and Brazil's squads have each faced a combined workload of more than 30,000 minutes since the beginning of August, more than double some other World Cup participant teams.

Meanwhile Virgil van Dijk, of Liverpool and The Netherlands, is the World Cup player with the most minutes played in the period between July 12 2021 and October 24 2022.

João Cancelo of Manchester City and Portugal, Sadio Mane of Bayer Munich and Senegal, Antonio Rüdiger of Real Madrid and Germany and Harry Kane of Tottenham Hotspur and England have also played more than 7,200 minutes in the same period - the equivalent of 80 games of 90 minutes.

FIFPRO consultant Darren Burgess, a high-performance director who has worked for teams including Arsenal and Australia, said there is "a really high risk" of injury for World Cup players, both because of overload and underload.

Burgess added that the lack of recovery time will expose those who reach the final stages to increased mental stress when they return to their clubs.

FIFPRO deputy general secretary Simon Colosimo said: "The data emphasises the mental and physical strain many national team players are facing because of a congested match calendar that does not properly consider their health and performance.

"I have no doubt each team will put on a tremendous show at the World Cup despite the challenging circumstances.

"However, all professional football stakeholders must refocus their priorities to ensure players benefit from a more balanced calendar and can perform at their peak during key moments of their careers."

Statistics have been gathered too on players making back-to-back appearances.

Tottenham Hotspur's Son Heung-min, who captains South Korea, played more than 600 minutes in back-to-back games in the first 23 days of October.

Back-to-back matches are appearances with less than five days of recovery time between them, making players more susceptible to muscle injuries.

More than 70 per cent of matches played this season by Kane and Kylian Mbappé of France and Paris Saint-Germain were also back-to-back.

The report, prepared in cooperation with Football Benchmark, also looks at individual players with excessive travel and workload including Son, who since July last year has completed 146,104 kilometres of international travel.

Mbappé, 23, has already played 27,000 career minutes - the equivalent of 300 games of 90 minutes.

The report adds: "However, overwork is not exclusive to Europe's 'Big Five' leagues.

"Six of the top 20 most-used players over the last 16 months play club football elsewhere: in Belgium, Brazil, England's Championship, the Netherlands, Portugal, and the United States…

"While some players and teams face overload, underload could be a significant issue for many teams from Africa and the AFC [Asia] region, including Australia, Cameroon and Qatar.

"The latter had the least amount of game time, ahead of Saudi Arabia and Iran.

"Qatar’s players prepared with the unusual strategy of a six-month training camp."