The incident occurred late in the first period of Monday's 7-4 Blues win. During a scrum near the Coyotes goal, Crouse engaged Buchnevich with a cross-check for which he was given a two-minute minor penalty. In response, Buchnevich deliberately head-butted Crouse and he was ejected from the game with a match penalty.
Buchnevich is considered a repeat offender after he was suspended one game for high-sticking the Capitals' Anthony Mantha last season.
The Blues acquired Buchnevich in an off-season trade with the Rangers.