The number of matches being played by elite footballers is becoming unsustainable and is leading to a heightened number of injuries, believes Borussia Dortmund coach Nuri Sahin.

Sahin was speaking ahead of BVB's Champions League meeting with Barcelona, for which the Bundesliga side will be without a string of players including Niklas Sule, Waldemar Anton and Julian Brandt.

They have been beset by injuries this campaign and were at one stage without 10 players, while they are also among the teams to qualify for FIFA's expanded 32-team Club World Cup next year.

"It is not an excuse. I am not searching for an excuse... but it is a fact that especially for national team players the burden is almost unbearable," Sahin said on Tuesday.

"Because yesterday for example we planned the season with the Club World Cup and I don't know when [goalkeeper] Greg [Kobel] will go on holiday."

The expanded Club World Cup will run from June 15 to July 13, 2025 in the United States, cutting into players' summer holidays in a year without a World Cup or a continental competition in Europe, Asia or South America.

The 2025-26 domestic campaign will begin just a few weeks after the tournament ends, while the Champions League's new format also means elite sides are tasked with two additional group-stage games per season.  

"The players travel from A to B and from B to C but it is not only the matches," Sahin said. "The game itself has changed as well.

"I am not that old but some 10 or 15 years ago the game was different with fewer sprints, less running. Now you have to go completely to your limit in every game.

"I don't think FIFA will change it now because Nuri Sahin spoke out but I feel that the burden for national team players is way too high.

"You see it in the top teams. You mentioned Bayern Munich. Barcelona, many injuries, Real Madrid, many injuries. You can go through them all. I don't think that will change." 

The draw for next year's Club World Cup took place last week, with BVB drawn into Group F alongside Brazilian giants Fluminense, South Korea's Ulsan HD and South Africa's Mamelodi Sundowns.