It's Subban's second injury since he was acquired in a trade with the Chicago Blackhawks on Dec. 2. He missed three games with a lower-body injury after he was injured during his Sabres debut Dec. 4, and was 0-2-1 with a 4.85 goals-against average and .871 save percentage in four games (three starts).
"Likely that he's not going to be able to be back for the season," Sabres coach Don Granato said Thursday. "It is tough because he's a happy guy, he's always got a smile on his face, he works hard. ... And then he starts getting in a little bit of a rhythm and comfortable around the guys and the team, and now it's a season-ending injury. So, yes, it is a bummer when you see a guy that's so excited and committed and now it looks like it's gone because it's right on the cusp of not being able to be back in time for the end of the season."
Subban is the latest Sabres goalie out with an injury. Ukko-Pekka Luukkonen (lower body) is progressing but remains week to week, according to Granato. Craig Anderson (upper body) hasn't played since Nov. 2, and Dustin Tokarski hasn't been cleared because of lingering symptoms from COVID-19.
The Sabres have used six goalies this season. They're 27th in the NHL in goals-against average (3.37) and 21st in save percentage (.901).
Aaron Dell is expected to start against the Dallas Stars at KeyBank Center on Thursday (7 p.m. ET; MSG-B, BSSW, ESPN+, NHL LIVE). Backup Michael Houser signed a one-year contract Jan. 12.
Colin Miller had surgery for a lower-body injury and the defenseman is expected to be out at least six weeks, Granato said.
Kyle Okposo is week to week with an upper-body injury the forward sustained on a hit from Ottawa Senators defenseman Erik Brannstrom in the third period of a 3-1 win Tuesday.
"He'll plow through this I'm pretty certain, pretty quick," Granato said of Okposo. "But he's dealing with some bumps and bruises from the game the other night that need to be worked their way out."
Vinnie Hinostroza (lower body) will be out at least three weeks. The forward was injured during a 3-2 overtime loss to the Detroit Red Wings on Monday.
Defenseman Jacob Bryson (upper body) and forward Zemgus Girgensons (lower body) each is day to day. Girgensons is eligible to come off injured reserve Friday and could play against the Philadelphia Flyers on Saturday.
Casey Mittelstadt was a full participant in the morning skate Thursday and is close to returning. The forward will miss his 15th game following surgery for an upper-body injury sustained Dec. 7. He previously missed 21 games from Oct. 16-Dec. 1, also with an upper-body injury.
"Big thing is to get him integrated in practice, see where he's at," Granato said. "We'll get another practice in tomorrow and we'll see where he's at. So no timetable yet for the next game but he's going be back within the next couple is my guess with 'Mittsy' based on where he's at."