United boss Sir Alex Ferguson will definately not be able to name the injured Darren Fletcher, Danny Welbeck and Ji-sung Park in his squad for the game at Old Trafford and Gary Neville is ruled out through suspension.
"Ferdinand and Vidic are both doubts - we'll see what they're like today," Fergie has said.
"Gary Neville is suspended of course.
"Hopefully we can get one or two fit for tomorrow but we're facing an uphill fight.
"Vidic has had a calf problem for a few weeks now. We've seen a specialist about it so we'll see what he's like today.
"Rio and Vida both want to play after the disappointment of last Sunday."