The Red Devils dropped points for the fourth time this season after drawing 1-1 with Wolverhampton Wanderers on Saturday.
Jose Mourinho's men find themselves in seventh position, eight points behind leaders Liverpool.
"Everyone is disappointed," the Belgian told Premier League.
"We know we can do better.
"We had to win today because after that it will be difficult to close the gap. Everyone is disappointed, but that is football.
"We have to move the ball quicker, when we create the chances we have to score."