"Psychologically, it will not mean more," said Ancelotti.
Related ArticlesChelsea transfer ban suspendedChelsea v Manchester United: match previewGourlay's Chelsea pledgeDeco: Didier Drogba better than Wayne RooneyDebate: Drogba v Rooney"We have to play against a strong team. We will play against the second team in the list of the Premier League, but I think that it's just a game that carries three points like the others.
"It's a very important game. It's important because we play against a fantastic team, but we know very well that it will be a very difficult match but also a very interesting one.
"We are happy to play this game at this moment. I think we are doing very well, we are in good condition and we have a very good mental attitude."
United will be without calf injury victim Rio Ferdinand in defence but Ancelotti does not think Sir Alex Ferguson's side will be vulnerable as a result.
"I think Manchester United have a very good team," added the Italian.
"Like us, they are doing very well because they have qualified in the Champions League and have done very well in the Premier League.
"Sometimes against Ferguson I've won. Sometimes he's won. But it's not a match between Ancelotti and Ferguson. It's Chelsea v Manchester United.
"I have a very good relationship with Ferguson. I think that he's one of the best coaches in the world. He has won a lot of trophies and I have respect for him."
But Ancelotti will not entertain the idea that the title race is a two-horse affair between them and United, citing a rejuvenated Arsenal as being very much in the mix.
"I think Arsenal have good possibilities to arrive in first place," he added.
"We can't think about Liverpool at this moment because they are behind, but Arsenal have a very good team and a very good chance to win."
Didier Drogba will provide Chelsea with their most potent threat. The Ivory Coast international is arguably Europe's top striker at the moment but Ancelotti does not see Sunday's game revolving solely around the striker.
"He's doing very well for the team, but not only Didier is doing well, all the squad are in good condition and doing very well," he added.
"To win against Manchester United, we cannot win only thanks to Didier's work. We can only win if we play like a team."