City will face Saudi side Al-Hilal in the last 16 of the tournament on Monday (30.06.25) but the coach is concerned about how the lack of rest for his players this summer will impact the team's Premier League campaign next term.
Guardiola said: "After this, let's see what happens. Let's see what happens after the final. We can rest and take the time that the Premier League has allowed us to rest and then we will see.
"Maybe in November, December or January, it will be a disaster, we are exhausted and the World Cup has destroyed us. I don't know, but it's the first time in our lives that this has happened.
"Mentally, I think in the past the players have played in World Cups or European Championships for their national teams, so it happens sometimes. You need a rest mentally sometimes, you can recover and then we will see when we come back."
Guardiola's former adversary Jurgen Klopp has branded the Club World Cup as football's "worst idea ever" and the City boss can understand Klopp's comments - but suggested that other teams would love to be in his side's position.
The Spanish coach said: "Listen, I fought a lot with Jurgen many, many times. I know where his idea comes from. His comments [on the Club World Cup] didn't surprise me a lot. I understand him. I respect him. Now, he's stepped back from that position [as a manager] and I understand his argument, because I would defend his argument, as well.
"As managers, we don't organise the competitions. Once we are here, we are proud. Many, many teams complain about these competitions because they are not here; otherwise, they might love being here."
Guardiola added: "They would have their media and supporters here, and there would be income to be here and they would be happy to be here. Of course, it's not an ideal situation for the manager. Would I love to have two months to prepare for next season? Yes. Would I love to be refreshed for next season? Yes.
"But it is what it is. And we deserve what we have done in the past to be here. Once we are here, let's do our best possible."
