Rio Ferdinand is thought to have a chance of returning to the United line up tonight after being withdrawn on Saturday with a groin injury. However it is now reported to be unlikely that Gary Neville will return until next week. John O'Shea is also struggling to be fit for tonight, and if neither he nor Ferdinand are fit then Ferguson will face a dilema over the right-back position.
Darren Fletcher could continue in the role after filling in during the semi-final, but youngster Craig Cathcart may be given his debut after appearing on the bench at the weekend.
Sheffield United also have some injury problems. The centre-back Claude Davis is almost certainly out of tonight's game and striker Jon Stead, also picked up a knock on Saturday and may not figure tonight.
Warnock is certainly not confident of a victory, "It's a bit sadistic putting this game on television, but that's producers for you. It's a game nobody will give us a chance of getting anything out of. I think the bookies' odds will be just on how many goals we concede. A win would be a miracle and the result of the decade, not just the season, with the way they are playing at the moment.
"How do you cope against a team who are, without a shadow of a doubt, the best in the world right now? There is no other team that has a forward line like Manchester United, and I would have thought they all want to play against us. They will all be thinking it's a great opportunity to score a hat-trick, and quite rightly so looking at the fixture.
"But we've our own pride. The fans will be crossing the Pennines, and we want to put on a show, as we always do. And then it's not just pride we're playing for because we don't want to end up being humiliated."