Hammond suffered the injury during the Canadiens' 5-4 overtime victory over the Flames on Thursday night in Calgary.
The veteran netminder's 30-save performance improved his record to 3-0-0 since joining Montreal last month. He also boasts a 2.40 goals-against average and a .920 save percentage.
Primeau, meanwhile, has appeared in 11 games with the Canadiens this season.
He has also compiled an 11-9-1 record with the Rocket this year, along with a 2.80 goals-against average, a .912 save percentage, and two shutouts.
The 22-year-old was a seventh-round selection of Montreal (199th overall) in the 2017 NHL Draft.
