The forward left the Jets' 4-2 loss in Game 4 on Monday with 14:49 remaining in the first period after sustaining an upper-body injury.
Since winning Game 1, the Jets have lost three straight and trail 3-1 in the best-of-7 series.
"Mark, we're ruling out for tomorrow," Jets coach Rick Bowness said on Wednesday.
Scheifele, who has one goal in four games in the series after leading the Jets with 42 goals during the regular season, was injured at 2:30 of the first when he slammed into the boards after tripping over Golden Knights goalie Laurent Brossoit on a breakaway. Scheifele returned to the ice for a power play about two minutes later but went to the locker room after attempting one shot.
He is the latest addition to the list of injured Jets players, along with defenseman Josh Morrissey (lower body), forwards Nikolaj Ehlers (upper body) and Cole Perfetti (upper body), and goalie David Rittich (lower body).
Morrissey was injured in the first period of Game 3 and will miss at least the rest of the series. He had one assist in three games and was second on the Jets during the regular season with 76 points (16 goals, 60 assists) in 78 games. He also led Winnipeg with an average ice time of 24:14 per game.
RELATED: [Complete Golden Knights vs. Jets series coverage]
Ehlers, out since April 11, was a game-time decision for each of the first three games of the series but did not skate ahead of Game 4.
Bowness, who has been an NHL coach or assistant since 1984, said the Jets' list of injured core players through their first four games of the Stanley Cup Playoffs is unlike anything he's ever experienced.
"No, not to your key guys," he said Tuesday. "When's the last time you saw a goalie (Connor Hellebuyck) get cut in the head? And the kind of injury Morgan (Barron) had? But again, that's what playoffs are. And you just persevere, you deal with it and you move on and get ready for the next shift."
Barron returned to Game 1 after the forward fell onto the skate of Brossoit during a net-front scramble. He needed 75 stitches to close the cut.
"We haven't had good luck so far," Hellebuyck said. "We've been playing pretty good though, despite all of our adversity. Now we have to make sure our heads are right and know we're in for the grind and we're not out yet."
Hellebuyck was cut above his left eye in Game 2 when he was hit by a shot from Vegas forward Jack Eichel, but never left the ice.
"Game 2, took one right in the eye, you don't love that," Hellebuyck said. "It's pretty rare, to go puck in the cat eye. Last night, puck in the mask, dents my cage. I don't think it's that rare, it happens, but I've been taking a beating. I don't mind. This is playoff time. It makes you realize how much you're giving and how much more you care. I like a lot of things about my game. I'm going to continue to improve and really wait for this script to get flipped."
Had Hellebuyck needed to come out, it would have been
Arvid Holm
replacing him because Rittich was unable to dress for Game 4.
"We'll find out tomorrow if Rittich is] able to put a skate on," Bowness said Tuesday. "He's got a lower-body thing going on. We'll see. We won't have an answer to that until [Wednesday]."
In addition to Holm, who was recalled from Manitoba of the American Hockey League on an emergency basis Monday, goalie
[Oskari Salminen
was recalled from the AHL on Tuesday, and each traveled to Las Vegas as insurance.
"You just never know," Bowness said.
Perfetti, who had 30 points (eight goals, 22 assists) in 51 games, last played Feb. 19. The 21-year-old returned to skating in a non-contact jersey April 8 and travelled with the Jets, but will not play in Game 5.
Whoever is in the lineup, it's clear what's at stake.
"There's no choice. We have to be confident," Bowness said. "We have to be, and we will be. We'll be a very confident group going into that game. We're going to have a swagger to us that says if we go out, it's going to be one tough fight. When we play with that attitude, then I like our chances."
