Carlo Ancelotti insisted Real Madrid will reject FIFA's invitation to participate in the Club World Cup in 2025, citing a lack of financial incentive for the 15-time European champions.
The revamped competition has been expanded to allow 32 teams to compete in the tournament, which is set to take place in the United States at the end of next season.
It will be made up of teams from six federations, with Chelsea, Manchester City, Bayern Munich, Juventus and Madrid already qualified due to past success on the European and global stage.
FIFA have reportedly been discussing rights and prize money with clubs, but with concerns over player welfare due to a bulging fixture schedule, Ancelotti, who has won the competition three times with Milan and Los Blancos, believes it is not worthwhile for the LaLiga champions.
"FIFA can forget it, footballers and clubs will not participate in that tournament," Ancelotti told Italian daily Il Giornale in an interview published on Monday.
"A single Real Madrid match is worth €20million and FIFA wants to give us that amount for the whole cup. Negative. Like us, other clubs will refuse the invitation."
The 65-year-old led Madrid to their 15th European crown following a 1-0 victory over Borussia Dortmund at Wembley.
Ancelotti returned to the Bernabeu in 2021 after leaving Everton, and was keen to highlight the pressures of being a coach in the modern game, revealing how he managed to stay passionate about his job.
"I see nothing particularly new, this has always been our job but the case of Jurgen Klopp is significant. The pressure continues, the burden of responsibility becomes too heavy, obsession takes over," he said.
"I keep my passion, that's how I live the match, the game, my job; I've always carried this balance with me. I've overcome moments that weren't always positive; after my experience with Everton I was off the radar, they thought I was finished, I was old."