Pronger and Rob Niedermayer hammered the Red Wings forward into the boards from behind in Game 3 of the Western Conference final Tuesday. Holmstrom, who had three points in the 5-0 win, was cut on the forehead and had to be helped off the ice - although he did return.
Pronger was not penalized while Niedermayer was given a five-minute boarding penalty and a game misconduct.
Replays appeared to show that Pronger got his elbows up and hit Holmstrom in the head. Game 4 in the best-of-seven series goes Thursday at the Honda Center.