Manchester United manager Alex Ferguson says team captain Nemanja Vidic may not return from knee surgery until late December, a month longer than initially thought.

The Serbian defender missed the final five months of last season after rupturing a cruciate ligament in his right leg. He then had surgery on the meniscus in the same knee in September that was expected to keep him out for two months.

But Ferguson said on Friday he believed a return for Vidic later this month was now unlikely, saying ''I think we're talking around December for Vidic. Maybe around Christmas time.''

United host Newcastle United on December 26.

United have other injury problems in defense with Phil Jones and Chris Smalling unavailable until later this month.