After Jean-Philippe Mateta had put Palace ahead from the penalty spot, United stormed back after the break with goals from Josh Zirkzee and Mason Mount.
Glasner said, "I don't want to talk about the missed chances. If we need more than one minute to be organised for a free-kick, it is our fault. How we scored is a penalty. It is how it is. We deserved to have the lead and then it is about small margins. I can't remember if Manchester United had a chance in open play but they were really good from set pieces and that's why we lost in the end.
"We can find many excuses, we can say fatigue, rotation, many excuses but the performances in many parts was good. Man United have played 50% less games this season. The result hurt, really hurts at the moment but we will learn from it. Sometimes learning hurts. We missed a couple of chances in July and August, in the transfer window, to make it easier for us but again we will stick together and make it better."
On making signings in January, he also said: "If you play European football for the first time in your history, you should invest and not save. We are doing well, we are still in a good position in the league and in all four competitions. I think January is too late. We will have played more than 50% of our games.
"Ismaila (Sarr) we lost him today with an injury and also he goes to AFCON so everything we are facing now, it's not surprising. Everything was pretty clear and I didn't say anything but today I think it is also time to speak about it that we missed the chance to play an even better season in the summer.
On Sarr after he went off injured. Glasner reported: "Quite swollen ankle."