Players have warned world soccer's governing body FIFA that they are ready to go on strike over concerns the playing calendar is overloaded, the chief executive of the Professional Footballers' Association (PFA) said Thursday, while global players' union FIFPRO is leading a joint lawsuit with several European leagues, including LaLiga and the Premier League.

Two days before the Champions League final between Real Madrid and Borussia Dortmund in London, the Premier League, LaLiga, Serie A and the PFA met to study measures to counteract FIFA's intention to increase the number of matches that footballers will have to endure next season with the imminent new Club World Cup.

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PFA CEO Maheta Molango, who has been calling for change since February, believes players have reached a breaking point. He says football's packed schedule endangers players' health and diminishes the quality of the sport.

"I can tell you a situation not 10 days ago where I went into a dressing room that was directly affected and said: 'I'm happy to be here and bark a bit, but ultimately it's up to you. How far do you want to go?"' Molango said on Thursday.

"Some of them said: 'I'm not having it, we might as well go on strike.' Some said: 'What's the point? Yes, I'm a millionaire, but I don't even have time to spend the money.'"

Demands on players have increased in recent years, as tournaments expanded and new competitions emerged, with players and managers saying that the calendar demanded too many matches.

"It was not even the union that said it, it was Jurgen Klopp and Pep Guardiola. We have reached a point where we cannot rule out any action," Molango said.

Global players' union FIFPRO, along with the PFA and the World Leagues Association (WLA), continue to threaten legal action if FIFA does not change course.

In a letter addressed to FIFA president Gianni Infantino and general secretary Mattias Grafstrom, they expressed their concerns over the expansion of the new 32-team Club World Cup.

In response, FIFA denied their claims it had taken unilateral decisions to favour its competitions in the international calendar and would not consider rescheduling the tournament.

"Some of the changes in England with the domestic calendar have been forced by what FIFA and UEFA have done. What has happened is further confirmation that something needs to be done," Molango said.

"We will always try to exhaust all diplomatic avenues, we have sent a letter, we have received a reply, but unfortunately time is against us. Sometimes between grown-up people, despite trying very hard to find solutions you need a third party to decide, maybe an arbitrator or a tribunal."

Information from Reuters was used in this story.