United's Rio Ferdinand will be out for 10 days

Rio Ferdinand faces a 10-day lay-off after being forced to pull out of Manchester United's victory over Stoke City with a recurrence of a back injury.

The centre-back was named on the team-sheet at the Britannia Stadium but was withdrawn minutes before the Boxing Day kick-off when the problem flared up and he was deemed unfit to start the game. Ferdinand's place was taken by young Northern Ireland defender Jonny Evans and the England international has now been ruled out of the rest of the Christmas and New Year programme.

"We have to get to the root of this because he has had this problem too many times now," said United manager Sir Alex Ferguson. "We have to get to the bottom of it. It will be a week to 10 days and then he should be okay."

His injury means Ferdinand will miss Monday's visit of Middlesbrough to Old Trafford and the FA Cup third round tie at Southampton the following Sunday. The defender, who would almost certainly have been rested for the first leg of the League Cup semi-final with Derby County on Jan 7, will now target the visit of Chelsea to Old Trafford four days later for his return.