Speaking in a recent interview, the 47-year-old said his plans in England are to dethrone the 20-time league champions and rivals United.
"No surgery is required, and the midfielder is expected to be out for around three months".
"We never know. My opinion is that when you ask a lot of the players, over more than 11 months, then after he comes back, this (injury) can happen", Guardiola told reporters on Friday.
Tottenham have moved their first three fixtures to Wembley, where they played home games last season, but switching the City match to the national stadium is complicated because an NFL game scheduled for the same day.
The Belgium worldwide cut short his holiday to ensure he was in contention for selection ahead of City's opening weekend win at Arsenal and played the final half an hour as the champions coasted to a 2-0 win at the Emirates.
Greek tragedy as AEK knock Rogic's Celtic out of Champions League
Celtic will next face either Latvians Spartaks Jurmala or Lithuanian outfit Suduva for a place in the Europa League group stage.
"It's especially part of the game for the players - it's normal, they don't rest". They (the football authorities) say "let's go" and we are in the competition. "Of course human beings have a limit and sometimes these things happen".
"Nobody knows, but I'm pretty sure this can influence it". If you disagree, complain to me for my decisions.
Toure: "I think the point of what I'm saying right now is that it's true because in the first half we were there, but in the second half they took us physically".
Speaking during his press conference ahead of Sunday's Premier League clash against Huddersfield, City manager Pep Guardiola revealed that David Silva could be in contention to start at The Etihad and that is a major boost for Fantasy Football managers around the world. "Last week he was not fit, he had a little problem in his leg, but he has been training good this week".
"He is one of the most interesting and fascinating players in the whole history of Spain".