The Arizona Cardinals didn't know its severity, either.
Wilson, who underwent surgery early this month, started all 16 games.
"It's pretty apparent that he was affected," Whisenhunt said this week from the NFL owners meeting. "Any time you have the type of injury that he had, it's very difficult to change direction, to move."
The Cardinals expect Wilson to achieve previous form once he's healthy and the labor situation resolves itself.
"I think Adrian embodies a lot of what we're trying to get accomplished with that team: the toughness, the ability to show up every week," Whisenhunt said. "And even though he didn't play as well as he wanted to play last year, he still fought the fight. I think that is a credit to him.
"We didn't know how bad it was until afterwards and that is maybe something you have to make sure as you go forward that you can't fight through everything. But I have a tremendous amount of respect for what he did and I believe that this year we will see more of the old Adrian because he'll be healthier."