Defensive concerns mount for Man Utd
Rio Ferdinand is the biggest miss for United at present, with the England international set to undergo a scan in order to determine the full extent of a his thigh strain.
"Ferdinand will be out for two weeks - the next two or three games I would think," the Scot.
"(Nemanja) Vidic is training so, hopefully, we'll have him back for next Saturday at Wigan.
"Jonny Evans is injured again, Gary Neville has just resumed training and Rafa da Silva is still out with a dislocated shoulder.
"We've had a hard time with defensive injuries over the last two years but have good replacements who have experience."