Chelsea boss Carlo Ancelotti admits their draw at Stoke City has hurt their title hopes.
Having got themselves back into the game when Didier Drogba's 33rd-minute header equalised Jon Walters' early strike the Stamford Bridge side failed to build on that.
"We did our best. It was a good result because Stoke had opportunities," said Ancelotti.
"They could have won, we could have won. It was exciting.
"We have to continue to do our best. The gap (to United) was not easy before this game and now it is more difficult but we have to think game by game.
"We didn't think about this (the gap) before this game and we don't have to think about it after this game.
"The gap is more open now but we have to play our game. It is not about Manchester United.
"I think it is very difficult (to win league) - we said that before the game."
