Blues Head Coach Craig Berube made the announcement to reporters during his availability with the media on Sunday morning.
Thomas scored the Blues' only goal early in the first period in Saturday's 3-1 loss against the Arizona Coyotes. He had three minutes and one second of ice time before leaving with the injury.
"Well, I mean, somebody else is going to get in that position and do a job for us," Berube said of losing Thomas. "That's the way we've got to look at it. We've got players. We're a deep team and that's a good thing. Other guys get an opportunity to get in there now and play."
Thomas has one goal and five assists (six points) in 12 games this season.
