The Red Devils comfortably negotiated their way past Palace thanks to a brace from Marouane Fellaini sandwiched between goals from Juan Mata and Romelu Lukaku.
United are yet to lose in the Premier League this season, but after the upcoming break they face a tricky schedule of away games.
They travel to Liverpool, Benfica in the Champions League, Huddersfield and then Swansea before a home fixture against an in-form Tottenham.
"I don't welcome the break, it's bad," said Mourinho.
"We had the first break and two days after the players came back we had to play another game. It's not a good situation for us but moaning doesn't help. We have to wait for them and hope there are not many problems."
Despite Saturday's comfortable win, Mourinho still believes there is room for improvement in the United squad.
"I told the players that we had to respect an opponent in a difficult situation, an opponent better than their results show," he said. "It was important to respect them and play seriously.
"The result is probably bigger than our performance because I don't think our performance was consistent. We had good periods, good moments, and we always had control of the game, but we can do better. The important thing is the three points."