The Reds have already won at Stamford Bridge this season, beating the Blues 3-2 in the Barclays Premier League, but a less experienced line-up lost there three days later in the Capital One Cup, going down 5-4 after extra-time.
With former Liverpool chief Rafa Benitez since installed as interim manager, there is added spice to the occasion. The Spaniard's first meeting with United as Chelsea boss ended 2-2 three weeks ago when only a late David De Gea save prevented Juan Mata from completing an incredible comeback by the visitors.
"I thought we were lucky to be honest with you," stated Sir Alex. "I thought that tiredness had got into the team and, from a comfortable position for the first 20 minutes, you could see the signs when we started to give the ball away just before half-time. That is a definite sign of tiredness.
"The tiredness came, possibly, from the emotional intensity of the Real Madrid game and also the way we lost it. I think that affected two or three players. In the second half in particular there was no doubt that Tom Cleverley’s and our two full-backs’ [Rafael and Patrice Evra] legs had gone. That was [due to] emotions. The way full-backs are, they put so much energy into getting forward but they found it difficult getting back.
"That made it a long game against Chelsea and they had the advantage of extra players in midfield. They really deserved to win the game in the second half, although we could have been four-up in the first 20 minutes. De Gea’s save was one thing, but I also thought we were scrambling about to get through the game. But we’re fresher now and we’ve got a strong squad in terms of