Walman (upper body) left Tuesday's game versus the Panthers early, Lou Korac of NHL.com reports.
The nature of Walman's injury isn't clear, but he suffered it on the same play midway through the third period that left Ville Husso (lower body) ailing. The Blues played Tuesday's game a man short, so they'll be able to make emergency recalls for Thursday versus the Red Wings if any of their injured players are unable to suit up.