The England international was forced to come off just before half-time of United’s Champions League fixture against Cluj and has been diagnosed with a calf strain.
With the talented midfielder unlikely to recover in time for Sunday’s clash against Manchester City, Sir Alex Ferguson is facing a genuine selection headache.
Anderson, Shinji Kagawa and Nani are definitely out, while Antonio Valencia is unlikely to return after missing the last five matches with a hip problem.
That basically means that Fergie only has experienced midfielders Paul Scholes, Ryan Giggs, Michael Carrick and Darren Fletcher at his disposal, with youngster Nick Powell unlikely to feature in such a high-profile game.
Numerous selection problems could be the main reason why United are 3.50 (5/2) with BetVictor to win at Etihad. The Red Devils are 2.00 (1/1) with Betfair to pip their rivals to the Premier League title.