Manchester United have been dealt another injury hammer blow after skipper Nemanja Vidic was ruled out for eight weeks following knee surgery.
Vidic, who missed the final five months of last season after rupturing his cruciate in the Champions League defeat to Basle, missed Sunday's Premier League win at Liverpool after complaining of tightness in his right knee.
However, a subsequent examination revealed a greater problem, prompting Vidic to be sent for an operation, which has now been completed.
"Nemanja Vidic has had a meniscus operation on his right knee and will be out for around eight weeks," said a club spokesman.
"Sir Alex, as a precautionary measure, rested Vidic at the weekend, after he complained of tightness in his knee, however, further medical investigation revealed the underlying problem.
"The central defender was operated on this week and will be sidelined for about eight weeks."
As the new injury is the same knee as Vidic ruptured his cruciate, it is bound to spark fears of another major problem for the 31-year-old defender.
Even on the timescale United have highlighted it would rule the Serbian out of the Red Devils' next three Champions League matches in addition to seven Premier League games, including key meetings with Chelsea and Arsenal.
However, the worry must be that Vidic will be out for even longer, robbing Ferguson of a major component of his entire squad.
But in the short-term, it provides the United boss with a major headache.
As Phil Jones has been ruled out for a similar period of time with the same problem, and Chris Smalling is yet to resume training after a broken metatarsal, it leaves Ferguson with only two fit central defenders. However, Jonny Evans picked up a knock at Anfield.
It continues an unhappy sequence of defensive problems for Ferguson.
Already this term Michael Carrick had been forced to play in that position twice as an emergency measure.
Last Friday Ferguson said he was crossing his fingers Vidic, Evans and Rio Ferdinand remained fit.
Those hopes have now been dashed and it remains to be seen who United have to call on ahead of Saturday's Premier League encounter with Tottenham at Old Trafford.
It also suggests Michael Keane and Scott Wooton may be in line to face Newcastle in Wednesday's Capital One Cup third round tie. Nineteen-year-old Keane has made one substitute appearance for the senior side, whilst Wooton, who went on the summer tour to South Africa and China, is yet to make his debut.
England Under-18 international Tyler Blackett could also be involved.