The league confirmed the suspension Wednesday.
Not surprisingly, Smith will appeal the suspension. Equally unsurprising is the Houston Texans defensive end's contention that the incident played out differently than the league might believe.
"I didn't swing (the helmet) at him," Smith said, according to the Houston Chronicle's John McClain. "I was restrained. I caught myself. I did it out of frustration, but I brought the helmet back slow to my body so I wouldn't hit him. I think the suspension is a little harsh because I restrained myself."
"I will appeal. Anybody would in this situation," Smith added. "I want to state my case. I've never had anything like this before. I'm surprised it included a regular-season game."
Smith has support in his own locker room. Running back Ben Tate expressed frustration on Twitter that the NFL has not disciplined Incognito for either of his run-ins with Smith.
"I'm very disappointed about it," Smith said. "The biggest thing is, I won't be there to help my team. I'm disappointed that this all came about. I won't be able to be there when my team needs me."