Manchester United have concerns over Nemanja Vidic.

The Times says Vidic has yet to make an appearance in the six pre-season matches, having missed the tour to Asia because of an ankle problem and then strained his calf during the warm-up before the 2-1 victory over Boca Juniors on Wednesday.

The Serbia defender will hope to figure in the home match against Valencia next Wednesday and the Community Shield against Chelsea four days later, but a series of injuries to defenders is a concern for manager Sir Alex Ferguson, with the opening Barclays Premier League fixture, at home to Birmingham City, only 16 days away.

Wes Brown sat out last night's game with a calf problem, while Rafael Da Silva and Gary Neville are back in Manchester with a dislocated shoulder and a groin injury respectively.