United were 1-0 up in the game against the Swiss side, but lost Aaron Wan-Bissaka to a first half red card.
Following the dismissal, manager Ole Gunnar Solskjaer went defensive in a bid to hold onto the lead.
As they went on to lose the game 2-1, and did not manage a single shot since the red, Schmeichel believes Solskjaer got his tactics very wrong.
Schmeichel said, per The Sun: "'We can always question team selection, I just think when your next game is Sunday at West Ham, first game in the Champions League – why don't you play your best team, your best players?
"Regardless of astroturf, whatever excuses you come up with, get that win there.
"I think when you look at Mason Greenwood, he's in great form, he's a young man, he creates chances and not only does he score he creates chances for others."