The Spaniard's place in the side has been questioned this week following his part in United's 1-1 draw at Tottenham Hotspur on Sunday.
De Gea was held largely to blame for Spurs' equaliser in the Premier League encounter as his punch from a corner led to Clint Dempey's injury-time goal.
"It is very easy to claim De Gea is to blame," Schmeichel told Sky Sports News. "I disagree. I think if De Gea had not played the way he did we would have lost 4-1.
"For the goal, David does all the right things. He got a fist to it under pressure but, unfortunately, the ball ends up with a Spurs player."
De Gea moved to Old Trafford from Atletico Madrid in summer 2011 for around £18m.