Manchester United's Rio Ferdinand remains hampered by a calf injury, and may miss the rest of the season, according to manager Sir Alex Ferguson.

The central defender has been out since February 5th, and Ferguson said that the Red Devils would be lucky to have him back by the end of the season.

This comes after learning the other central defender, Nemanja Vidic, will miss this Saturday's match against Bolton.

With Ferguson set to miss five games due to suspension, Manchester United has lacked good news recently.

Defenders Rafael will be out for roughly three weeks with a hamstring injury, while John O'Shea's hamstring injury was not a good one, according to Ferguson, and will be out for about a month. Jonny Evans is also nursing a knee injury.

The Red Devils will rely on Fabio, Wes Brown and Chris Smalling to step in for the injured players.