Manchester United could be without captain Nemanja Vidic for Monday evening's derby clash against Manchester City at Old Trafford.

The Serbian centre-back sustained a calf injury during the 1-0 victory over Sunderland last weekend and while it is not a serious problem, manager Sir Alex Ferguson has conceded that his skipper may miss the upcoming fixture.

"Vida got injured at Sunderland. Early on, he had a clash and had a bit of treatment and then he had a clash with David de Gea near the end of the game. It's not serious, just a nerve in his calf, so he should be maybe back in training over the weekend," Ferguson told MUTV.

"I've got Rio Ferdinand, Chris Smalling and Phil Jones so I've got the right cover, I think."

Vidic's fellow defender Jonny Evans is also a doubt for the match.