Manchester United manager Louis van Gaal says Saturday's 2-1 defeat at Sunderland is a step backwards for his side.
The Red Devils are now six points from the Top Four with Manchester City, Arsenal, Tottenham Hotspur and Leicester City all in action on Sunday.
"We didn't keep the ball in our team," van Gaal explained.
"For example against Chelsea we did do it and that is a big difference because you can control the game. We created chances in the second half, we could have scored also but that is not the problem.
"I think as Manchester United you have to keep the ball in spite of the pressure of Sunderland and create chances. We didn't have control in the second half. We didn't have control in the first 20 minutes, we had control in the second 20 minutes and we scored.
"[Why we lost?] Two set plays, two goals. We know in advance that they could score from set plays.
"They have a taller team, we have to organise it well but the main reason is that always in a match you shall be compared with your opponent in aggression.
"I think they played with more aggression because they play with direct balls so second balls are very important to win. We didn't keep the ball too much in our possession. These kinds of matches you have to win, I said that in advance, and we didn't do that.
"Of course [it is a backwards step]. What I said before the game was we have to win this kind of game and we didn't. We can only blame ourselves.
"I do my work to my utmost best. I cannot do more and I shall prepare my players against Midtjylland 100 per cent and I shall do that always.
"It [Matteo Darmian's injury] is unbelievable. It is a dislocation [of his shoulder] so he has several weeks out. We don't have any more full backs in this club."