Kotkaniemi scored two goals, one on the power play, in Friday's 5-0 win over the Flyers during Game 2 of their first-round series.
Kotkaniemi potted a goal in Monday's 3-1 loss to the Penguins in Game 2.
Kotkaniemi scored a goal on two shots versus Pittsburgh on Saturday.
Kotkaniemi (abdomen) is expected to be a full participant at Montreal's upcoming pre-postseason training camp, Arpon Basu of The Athletic reports.
Kotkaniemi will miss the remainder of the 2019-20 campaign with a spleen injury, Eric Engels of Sportsnet.ca reports.
Kotkaniemi (abdomen) is without a specific recovery timeline after returning to Montreal, Eric Engels of Sportsnet.ca reports.
Kotkaniemi suffered a splenic injury during Friday's game against AHL Cleveland.
Kotkaniemi had an assist, one shot and a two-minute minor in his first game for AHL Laval on Saturday.
The Canadiens assigned Kotkaniemi to AHL Laval on Saturday.
Kotkaniemi was a healthy scratch for Thursday's game against the Sabres.