Chelsea have lost seven games already this season in the league, the most they have lost since the 2003-4 season under Claudio Ranieri.
Ancelotti said: “It is difficult to think we can come back to fight for the title. It is better for us to think game by game in the Premier League. We have to reach minimum fourth place in the table.
“Obviously to close the gap (with United) is very difficult, we have to be honest, but the most important step now is to reach fourth place and we have to fight with the other teams.”