The Red Devils will have a chance to bounce back in front of their own fans against Young Boys in the Champions League tonight.
And Mourinho says his players are firmly focused on the task at hand.
He told MUTV: "I don't know another way. If you moan and stay in the dark because of a frustrating result then you are not able to compete in the next match.
"The fact that we play Saturday then Tuesday isn't good from the recovery point of view, but we had to train Sunday and today and we play tomorrow so everything goes really fast and you don't really have time to be thinking about what we could have done against Crystal Palace because it's over.
"It's about the next game and the next one. In practical terms even if we don't win tomorrow we have the last match to try to qualify, but I think we have to play the match tomorrow like it is the last one. I think it's the way we have to think, all of us… myself, the players and also the stadium. It's a bit of fiction but we have to think that this is the last opportunity we have and you have to win the match to qualify. That's the way to approach it."