While Pogba enjoyed a great World Cup with France, scoring in the final and winning the tournament, he has been hit or miss for United since the start of the season.
Rumors circulated in the summer about a possible move to Barcelona, but nothing materialized. And Schmeichel feels the player may be unfocused.
The legendary goalkeeper told talkSPORT: "Paul's come back from the World Cup having won it, he's come back very early and it's really difficult.
"I've obviously never been all the way to the final but I went to the quarter-final and to come back with very little break, very little holiday after you've been on this incredible high – you find yourself in this state that's been going on for three or four weeks and then it's gone.
"You completely deflate and to inflate yourself again it just takes time. Unfortunately, the football calendar is such that even the guys all the way to the final won't have much of a break.
"Hopefully later on in the season there is an opportunity to give those players just a little bit of a breather – it is so difficult, honestly.
"Your mind is somewhere else, you look at the 11 months ahead of you and think, 'This is the steepest mountain' and at some point you need to just get away from it.
"Hopefully he will get that."