Shortly after a face-off in the Blues' zone, Schwartz blocked a shot from Red Wings defenseman Mike Green and was helped off the ice by Head Athletic Trainer Ray Barile and Colton Parayko with 2:51 remaining in the period.
"I can tell you the initial x-rays were negative, but he's obviously really sore right now," Blues Head Coach Mike Yeo said after the game. "We'll get him re-examined when we get home."
Schwartz, who scored to give the Blues a 1-0 lead in the game, has 14 goals and 20 assists in 30 games this season.