The 18-year-old England striker, who moved to Old Trafford for 27 million pounds (40 million euros) from Everton on Tuesday, hinted that after a start to the season which sees Alex Ferguson's side ninth in the table and seven points adrift of the top two, the title might be beyond them this season.

"We've got some good young players at the club and providing we can all grow together in the team, I think we'll eventually come good again," the teenager told the club's website, www.manutd.com.

"It's a big challenge for us and we might not win the league this season; it might take two or three years. But I really think we're capable of matching both Arsenal and Chelsea."

Rooney will have to wait for his debut as he is till suffering from a broken bone in his foot, a legacy of his sensational performances at Euro 2004.

"Going out to Portugal was a big experience for me and after doing as well as did out there, I felt that I had moved my game on and I wanted to be playing in the Champions League," said Rooney.

"I think it will be a different type of challenge and a difficult one too because you'll be up against the top players in Europe.

"But that's what every player relishes; they want to challenge themselves and play against the best players, and hopefully we can go out there and win it."

Rooney has come under intense scrutiny in recent weeks with various lurid allegations involving his private life keeping large sections of the tabloid press busy.

But he believes his is still maturing as a player and a person.

"I think I've changed a lot as a person on the field and off the field," he said.

"I'm much more mature than I was 12 to 18 months ago, but that all comes with playing the game.

"Hopefully I can keep my head down, do my job well and go out and do my best for Manchester United. He (Ferguson) has worked with a lot of young players over the years and he's always got the best out of those players.

"Hopefully he can get a lot more and the best out of me over the next few years."

The prospect of linking up with the likes of Ruud van Nistelrooy, Roy Keane, Ryan Giggs and Paul Scholes is one which excites Rooney, and he is confident he can learn from them too.

"I'm very excited," he said.

"There's a really good squad of players here who are all top players. I hope I can gel as quickly as possible and become one of those players as well.

"They've all got great experience of playing at the top level and playing in the Champions League, so I think I'll be able to learn a lot from them, and if I need any advice, hopefully I'll be able to go and speak to them."