Primeau, 20, was Montreal’s seventh-round pick in the 2017 NHL Draft.
He spent the last two seasons with Northeastern University, posting a .933 save percentage, 2.09 goals-against average and 25-10-1 record in 2018-19.
Primeau is the son of Lisa Primeau and former NHLer Keith Primeau, who split 15 years in the NHL between the Detroit Red Wings and Philadelphia Flyers, recording 619 points across 909 games.
The young netminder’s parents were in attendance at the Bell Centre on Monday as Primeau appeared in his first-ever NHL game, a pre-season contest against the New Jersey Devils.
In a corresponding move, the Canadiens also sent 22-year-old defenceman Otto Leskinen to the Rocket.