Manchester United midfielder Owen Hargreaves says Wayne Rooney's hunger is key to his success.

The England midfielder hopes to make his playing return for the reserves tonight.

On Rooney, Hargreaves told the Telegraph: "He has always had great potential but with age and experience, he manages himself better throughout the game with the distances he covers, where he needs to be when the ball gets out wide. It's no coincidence that most of his goals are through headers because he is always in the box.

"At times, he has played on the wing because he is so unselfish and does so much work for the team. But a player of his calibre needs to play up front, centre-forward. He's been exceptional.

"The manager picks players with hunger like Roy Keane and Ryan Giggs, who is still around at 35. I'm sure there have been a lot of people with the same ability as Ryan but how many are willing to make the sacrifices? Most can't. A lot of people get caught up in the trappings that come with the game."