Manchester United boss Sir Alex Ferguson says he's amazed by Wayne Rooney's fitness levels.

Ferguson said: "His stamina levels are unquestionable. I'm quite amazed at him. Sometimes that can be costly, in the sense he can burn himself out and then for maybe 10 minutes he'll drop off a game. But then suddenly he explodes and away he goes again. He's amazing. He never stops. 'There are very few players with that desire and hunger.

"Sometimes he prefers to play towards the left side in that little corner in between players. He has created that role very well for himself.

"It's very interesting to see how he has changed his role a little bit."