Both players are struggling with calf injuries and did not feature in the Carling Cup win at Barnsley in midweek.
Ferguson said: "They will both want to play after the disappointment of last Sunday.
"But then we had the game on Tuesday. You have to get on with life.
"It was good for the young players to go away. Last year the ties were mostly at home.
"It is a different thing altogether and they acquitted themselves quite well."
Ferguson added: "Vidic has been bothered with his calf for a few weeks now. We have sent him to a specialist about it. We will see what he is like today."