Jacob Markstrom will be out 4-6 weeks because of a sprained MCL in his knee.
The goalie was injured during the second period of the Devils' 5-1 win against the Boston Bruins on Wednesday when Bruins forward Justin Brazeau crashed into him.
Markstrom remained down on the ice for several moments before skating off under his own power.
He is 21-9-5 with a 2.20 goals-against average, .912 save percentage and three shutouts in 36 games.
"It's kind of what I expected, maybe a little bit worse in terms of the timeline, but it is what it is," Devils coach Sheldon Keefe said Friday. "You got to take these things as they come; it's the reality of the League. Pretty much every team deals with it in some form or another.
"Obviously he means a lot to us. He's played extremely well. He's helped us pick up points when we haven't been very good and is a big part of our team, no doubt."
Jake Allen stopped all 16 shots he faced Wednesday after replacing Markstrom and likely will be in goal when the Devils play at the Montreal Canadiens on Saturday (7 p.m. ET; TVAS, CITY, SNE, NHLN, MSGSN2).
Allen is 6-8-1 with a 2.66 GAA, .904 save percentage and two shutouts in 15 games this season.
"He's just consistent and that's what you want in every player but especially a goaltender," Keefe said. "A guy who comes in every day, he's early to arrive, prepares himself extremely well, puts his work in. He's got perspective in being ready to play when it's his time but also supportive of 'Markie' when he was on a roll. So he's been in these situations before so he'll pick up and go and we'll support with our team play and keep pressing along as we did the other night."
The injury likely means Markstrom will be out for the 4 Nations Face-Off. He was one of three goalies named to Sweden's roster for the tournament, which will be held Feb. 12-20 at Bell Centre in Montreal and TD Garden in Boston.
"It certainly appears that way," Keefe said. "You never rule anything out with these types of things; sometimes it heals quicker than people think and sometimes it takes longer than you think. I don’t think there's any guarantees either way but I think the expectation now is he won't be on the ice between now and 4 Nations beginning and then he'll take it from there."
Sweden's first game is against Canada on Feb. 12 (8 p.m. ET; MAX, truTV, TNT; SN, TVAS).
Its other goalies for the tournament are Filip Gustavsson of the Minnesota Wild and Linus Ullmark of the Ottawa Senators. Among the options available for Sweden if it needs a replacement are Samuel Ersson of the Philadelphia Flyers and Anton Forsberg of the Ottawa Senators.
The Devils recalled goalie Isaac Poulter from Utica of the American Hockey League on Friday, and Keefe said Nico Daws also could see time in the NHL while Markstrom is out.
Poulter has yet to make his NHL debut. The 23-year-old is 8-7-3 with a 2.90 GAA and .897 save percentage in 19 AHL games this season. Daws had an .894 save percentage in 21 NHL games last season, and the 24-year-old is 4-12-1 with a 3.27 GAA and .892 save percentage in 18 AHL games this season.
"Poulter has done a good job," Keefe said. "Poulter will come on the trip [to Montreal] and stay ready and all of that. We've liked his development, but you'll see Daws as well."
NHL.com senior draft writer Mike G. Morreale contributed to this report
