Thomas suffered the injury midway through the fourth quarter as he was attempting to break up a pass intended for Cardinals wide receiver Chad Williams.
Seahawks head coach Pete Carroll defended Thomas' actions during his Monday appearance on 710 ESPN Seattle.
"He had it all just totally figured out and was as emotional as you can get," Carroll said. "... Give him a little slack. This is a very, very difficult moment that most people wouldn't understand what that was all about."
The Seahawks placed Thomas on injured reserve Tuesday. NFL Network's Ian Rapoport noted the six-time Pro Bowler's injury was a clean break and that he should be 100 percent healthy for free agency in March.
Thomas held out from all offseason activities hoping to secure a new long-term contract. He returned to the Seahawks on Sept. 5, four days before the start of the regular season. The 29-year-old recorded 22 combined tackles and three interceptions through Seattle's first four games.