Manchester United midfielder Owen Hargreaves is undergoing a double knee operation and has been ruled out for the rest of the season.

Hargreaves has been ruled out for the rest of the season after undergoing an operation on his right knee on Monday in a bid to cure a long-standing tendinitis problem.

Under the guidance of renowned Colorado-based surgeon Dr Richard Steadman, Hargreaves will have a further operation on his left knee in a few weeks as United seek to find a solution to a problem that has bothered Hargreaves since before his £18million arrival from Bayern Munich in summer 2007.

"Hopefully this has got to the bottom of it and we will get him back fit for next season," said United boss Sir Alex Ferguson.