Manchester United legend Denis Law admits he doesn't know why the club allowed Carlos Tevez to join Manchester City.

Law famously sent United down with City in 1974.

He told the Daily Mail: "He is an excellent player, a real trier who never gives up. I do not know why he didn't stay at Old Trafford, but he is one of the reasons why Manchester City have done so well this season.

"He has had a tremendous influence on City's results.

"I didn't get any hassle when I switched clubs. Maybe it's a wee bit different if you are foreign. It may make it harder.

"But he has been successful at Manchester City, so that makes it easier for him."