The NFL fined Suh $30,000 for unnecessary roughness because he kicked Schaub, but the league didn't suspend him because it couldn't reach a judgment on his intent.
Suh was on his chest after being taken down by an offensive lineman when he extended his left cleat and hit Schaub below the belt in Detroit's loss to Houston on Thanksgiving Day.
"I saw the play," Cunningham said, according to the Detroit Free Press. "I agree whoever said it on national TV that he has to have eyes in the back of his head. That's the first thing I said. I thought it was ridiculous. I'm so tired of having to say things like that, but it's true.
"I coach football for living, I've done it for a long time. All kinds of things happen. He was trying to make a play and nobody talks about the guard tackling him on the way to the quarterback. We get no call; they get a call -- or he gets a fine, whatever it was."
Schaub told a Houston radio station on Monday that Suh was not "Houston Texan-worthy," a statement Cunningham scoffed at.
"What is a Texan, anyhow?" Cunningham said, according to the Free Press. "You never make derogatory statements about another player and another team. If you say that, then say it behind closed doors and keep it that way. But you don't come out in the paper and start saying things like that.
"And, you know, I'm sure Matt's a great guy and he got caught up in the emotions. And I'll forgive him for it -- this time."
Information from The Associated Press was used in this report.