"Ben is not long term," Canadiens general manager Marc Bergevin said Tuesday. "He'll be back. We said 6-8 weeks. It's probably going to be closer to six, hopefully."
The defenseman was injured during a fight with Vancouver Canucks forward J.T. Miller in the first period of a 5-1 win March 10 and has missed the past three games. Montreal's final game of the regular season is scheduled for May 8.
"He's a big part of this team, on and off the ice," Canadiens forward Corey Perry said. "But this team is deep, and that's why we have guys that have put in the work and are staying fresh and staying ready and can step in. It's unfortunate what happened, but we'll take care of what we have to do here and we'll be looking for him to come back."
Chiarot has scored five points (one goal, four assists) in 25 games this season. His average of 21:22 of ice time per game is third on the Canadiens behind defensemen Shea Weber (23:01) and Jeff Petry (22:29). His 37 blocked shots are second on Montreal behind Weber (39).
Montreal, which visits the Winnipeg Jets on Wednesday (9 p.m. ET; TSN3, TSN2, RDS, NHL.TV), is fourth in the seven-team Scotia North Division, two points ahead of the Calgary Flames. The top four teams will qualify for the Stanley Cup Playoffs.