Jurgen Klopp has said that FIFA's plan to reshape the football calendar and stage a World Cup every two years is "all about money" and fails to consider the impact on the players who the Liverpool manager describes as "the most important ingredient."
A FIFA feasibility study into biennial World Cups, overseen by former Arsenal manager Arsene Wenger, has prompted vocal opposition from UEFA president Aleksander Ceferin.
But sources have told ESPN that there is growing support outside of Europe for the proposal to reduce the World Cup cycle from four years to two and Klopp said football is in danger of putting too many demands on the players who he fears will be expected to play without sufficient rest and preparation if the new proposals become reality.
"If there's a World Cup every two years that means, 100%, that there'll be a European Championship every two years which means top players will have a tournament every summer and maybe a three-week break," Klopp said. "That's the situation.
"At some point, someone has to start understanding that without the players -- the most important ingredient -- then we cannot play.
"There aren't many more relentlessly demanding sports as football. We all know why it's happening -- whatever people say about giving countries more opportunity in World Cup, in the end it's all about money.
"That's how it is. That's fine. We get a lot of money. But all things that have come out about reform, it's always about more games.
"We can never prepare for a season with our core players, in the long-term that's not right, but it's obviously not important what I say because nobody listens."
CONMEBOL joined Europe on Friday in opposing FIFA's push for World Cups every two years.
CONMEBOL's resistance to doubling the frequency of World Cups is striking given its president, Alejandro Dominguez, proposed the same concept to FIFA in 2018.
Now CONMEBOL thinks that biennial World Cups would lower the quality of the competition.
"There is no sporting justification for shortening the period between World Cups,'' CONMEBOL said in a statement that did not say if it was signed off by the 10 countries in the confederation.
"Although at some point CONMEBOL supported the project in question, technical analysis showed that it is highly unviable.''
European governing body UEFA has threatened to boycott the World Cup if FIFA doesn't stick with holding it every four years.
Klopp is planning to be without Liverpool's Brazilian players -- Alisson Becker, Fabinho and Roberto Firmino -- for Sunday's trip to Leeds after the Brazilian authorities protested to FIFA about the refusal of Premier League clubs to release South American players for the World Cup qualifiers amid concerns about COVID-19 restrictions when returning to the UK.
FIFA has imposed a ban on players playing for their clubs this weekend, although that decision could yet be overturned ahead of the weekend fixtures.
Guinea midfielder Naby Keita will be available, however, after Liverpool were able to fly the player back to the UK following a coup d'etat in his home country which led to the postponement of Monday's qualifier against Morocco.
"Naby is here and well and all fine, but it's not good as well," Klopp said. "We tried what we could do with other clubs to get him home safe. All other players are OK from international break."