"We sent him back (to St. Louis)," Blues Head Coach Mike Yeo said after an optional team practice at T-Mobile Arena on Thursday. "We figured he'd be out for the next couple games, so instead of having him travel all over the country, we figured we'd get him back home to see our doctor and checked out and try to get a proper diagnosis."
On Friday, Maroon was placed on injured reserve.
Maroon played 11 minutes and 19 seconds in Wednesday's game against Chicago, recording one shot on goal.
Overall, Maroon has recorded seven assists in 14 games since joining the Blues as a free agent.