Vidic may be out until Christmas
The Serbian defender was ruled out for a minimum of eight weeks after undergoing knee surgery in September.
But any hopes the 31-year-old might be back before the end of November have proved optimistic with Ferguson telling MUTV: "I think we're talking around December for Vidic. Maybe around Christmas time."
Vidic missed the last five months of last season with cruciate ligament damage but this latest problem is not related.
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