Tkachuk hit Red Wings forward Luke Witkowski on the leg with his stick in the third period while Witkowski was skating off the ice after being ejected for a game misconduct.
Tkachuk received a five-minute major penalty for spearing and a game misconduct.
The following grounds are being considered for supplemental discipline: unsportsmanlike conduct. However, the Department of Player Safety retains the right to make adjustments to the infraction upon review.
The Red Wings won the game 8-2.