Manchester United manager Ole Gunnar Solskjaer believes five or six clubs are capable of challenging for the Premier League title next season.
United haven't mounted a credible title challenge since Sir Alex Ferguson retired but Solskjaer believes that could change next term.
Asked about the difficulties United have faced since Ferguson's exit, Solskjaer told Norwegian TV station TV 2: "That's how football is now. You can never rest on any laurels, not that I think the club has done it, but it goes on for periods, up and down.
"United had an incredible period in the 1990s and 2000s, so we have had a tough period after Sir Alex, but we know the Premier League is a different competition now than when I played.
"Then it was us and Arsenal [challenging for the league], then came Chelsea. Now there are five or six clubs that can rightly think that they should fight for the trophy, so it is a completely different competition."
Solskjaer added that he is putting pressure on himself to bring success to United after a disappointing few years.
He said: "I don't care about the outside pressure and I do very well without it but internally at the club we have requirements, we have standards, but I think that I am the one who demands the most from myself and my players.
"I've always been that way. I am never completely satisfied, but then I never get completely down to the rim if things go bad either. You have to cope with both hardship if you are to survive in this club."
