Liverpool manager Juergen Klopp has slammed the idea of a World Cup every two years, saying the proposal was nothing more than an opportunity to generate more revenue at the expense of the well-being of players subjected to a "relentless calendar".
FIFA's Congress in May voted by a large majority to conduct a feasibility study into the potential of holding the World Cup every two years instead of every four years, with 166 national federations voting in favour of the study and 22 against.
Klopp said many radical ideas in recent years have been about scheduling more games which is not ideal long term.
"There's no other sport in the world with such a relentless calendar... We all know why it's happening. Whatever people say that it's about giving different countries opportunities, in the end it's all about money," Klopp told reporters.
"That's fine. But in the end, at one point somebody has to start understanding that without the players -- the most important ingredients of this wonderful game -- we cannot play it. Nobody is more important than the players.
"Imagine if every two years there is a World Cup and there will be a European Championship every two years. That means for top class players they play every year a big tournament. That means they have a three week break every year?"
Chelsea manager Thomas Tuchel said clubs were finding it hard to put up with losing players for internationals so soon after the season has begun, especially following the Euros and Copa America which were held in the off-season.
"It's very hard to accept because people want to see the top players on the pitch. If we only increase the games, that will not happen," the German told a news conference.
"In the end, we will not see top performances. That is not for the benefit of the game. I'm worried more about the actual situation than a revolution in terms of a World Cup every two years."