The pair sat out training today after picking up injuries during United's 2-1 defeat to Chelsea at the weekend.
Vidic got a kick in the face from Didier Drogba during the game on Saturday whilst Rooney picked up a hip injury before scoring the only United goal in the game.
"We will give them every chance," said Ferguson. "Nemanja didn't train yesterday and he didn't train today. Neither did Wayne train so it is a difficult one. "We think both could make it but I can't be dead certain about that."
I feel it's key Vidic and Rooney play for United tomorrow because both are such vital parts of the team. Ferdinand isn't the same player without Vidic at the back and United simply aren't the same without the presence of Rooney.
