Kolarov says they're determined to prove themselves superior on Monday.
He told Sky Sports News HD: "I have to be honest, they have been better this season.
"We have played good, but some games we have made mistakes. Against small teams, we have made a lot of mistakes - away especially.
"They deserve it because they are in first place at the moment. But, for us, that doesn't change anything. We are going to try and win in the game at Old Trafford, to be proud.
"They are confident in this moment and it will be a different game but - if we play like we know, if we are all at 100 per cent - I think we are better than them."