Pep Guardiola dismissed suggestions that the Premier League is a two-horse race between the Manchester clubs.
His City side and Jose Mourinho's United are equal top of the table with an identical record on points and goal difference after just five games of the season.
But champions Chelsea are just three points behind and Guardiola insists it is too early to write off any of last season's top-six, which also includes Tottenham, Liverpool and Arsenal.
"There are six teams [that can win the league]," he told a news conference ahead of Saturday's game with Crystal Palace, as reported by ESPN.
"All the other teams -- like Arsenal, Tottenham, Chelsea of course -- they are contenders for the Premier League but the important thing is to be there."
As well as sharing top spot, Guardiola also had similar views to Mourinho on the Carabao Cup following City's 2-1 win over West Brom in midweek.
The United boss suggested English clubs could benefit in Europe if the competition was scrapped and Guardiola, who made eight changes to his side for the trip to The Hawthorns, indicated that he agreed with Mourinho's comments.
Asked for his opinion on Mourinho's thoughts, he said: "[They are] quite similar, quite similar. So business is business. We have a lot of games.
"If you have to play in a competition you have to play in it. It's good for the people you don't use a lot," Guardiola said
"So for the managers, there's a lot of wasted energy. But we knew that before, so it's not a complaint in those terms. If we have to play, we have to play."
City face Palace on Saturday, who are without a point or even a goal in the Premier League this season. Vincent Kompany will come into contention after returning to training but Ilkay Gundogan will miss out due to injury.
It will be Roy Hodgson's second game in charge at Palace and Guardiola has huge admiration for his energy at the 70 and insists he will not be coaching at that age.
"He's had a long career and I respect that. I respect Gareth Barry for playing 600 games in the Premier League. I congratulate him. That is amazing. I love that. I love the people who stay there for a long time."