Interim manager Ralf Rangnick said Manchester United knows they can hardly afford to drop any more points if the Reds are to qualify for next season's UEFA Champions League by finishing in the Premier League's top four.
Manchester City showed their quality in the second half of Sunday's derby and a 4-1 defeat for United means the race for the top four is now an uphill struggle.
Rangnick believes United still can beat rivals Arsenal and Tottenham Hotspur to be in that leading quartet, but that the team will be taking it game-by-game.
The German coach after the match said: "I didn't actually expect Arsenal to lose at Watford so for us, it's clear, if we still want to have a chance to finish fourth at the end of the season, we can almost not drop any more points, and we also know that in those 10 games that we have to play, there are a few other difficult ones so let's take it game by game."
"For us, it's important we keep developing the team, which we did in the last couple of months, and then make sure we can win the next two home games against Tottenham and against Atletico, two very important games for us to come," he added.
The league leaders Manchester City are now on 69 points, six clear of second-placed Liverpool who have played a match fewer. Having lost for the first time in nine league matches, United drop to fifth, a point adrift of Arsenal in fourth having played three matches more.
