If center Sean Couturier is unable to play Thursday night in Game 6, the Flyers will need more than their big-boy pants to stave off elimination against the New York Islanders.

They will need their entire team to raise its level because Couturier, the Flyers’ MVP, plays in all situations and is their best all-around player.

Couturier suffered an apparent knee injury in a collision with Mathew Barzal late in the second period of the Flyers’ gritty 4-3 overtime win Tuesday, cutting the Isles’ series lead to 3-2 in the Eastern Conference semifinals.

The Flyers won the game Tuesday when Scott Laughton, who moved to Couturier’s spot on the top line, deflected Ivan Provorov’s point drive past Semyon Varlamov with 7 minutes, 40 seconds left in overtime.

Barzal, the Islanders’ top-line center who has 11 points in 14 postseason games this summer, did not play in the overtime. He was injured with 4:47 left in regulation when Claude Giroux’s stick accidentally hit him on the face on his follow-through.

Islanders coach Barry Trotz said he had only “moderate” concern about Barzal’s availability for Thursday. “I think everything is trending in the right area.”

Islanders left winger Josh Bailey whips a shot from behind that deflects off teammate Mathew Barzal and past Flyers goaltender Carter Hart. Barzal was injured in the third period of the game Tuesday but is likely to play Thursday.
Frank Gunn / AP
Islanders left winger Josh Bailey whips a shot from behind that deflects off teammate Mathew Barzal and past Flyers goaltender Carter Hart. Barzal was injured in the third period of the game Tuesday but is likely to play Thursday.

Flyers coach Alain Vigneault said he talked with Barzal on the elevator after the draining victory and was “happy to see there was nothing serious.”

While it seems Barzal will play Thursday, Vigneault was mum on Couturier (nine points in 14 postseason games) and said he was still being evaluated.

If Couturier can stand, you get the feeling he will try to play. Two years ago, he played with a torn MCL in his right knee and collected five points, including three goals, in a season-ending 8-5 playoff loss to Pittsburgh.

If Couturier can’t play, Vigneault will consult with his assistants Thursday morning about his replacement.

Laughton would probably remain on the top line and a change would be made on a lower line. Michael Raffl, if healthy, would seem to be the most logical replacement. Connor Bunnaman and Morgan Frost are other possibilities.

There is also an outside chance left winger Oskar Lindblom returns to the lineup for the first time since Dec. 7 and Giroux moves from left wing to center.

But is Lindblom, who has missed most of the season after battling a rare bone cancer, ready to play an important role in a must-win game that would be his first appearance in almost eight months?

Second-line center Kevin Hayes called Couturier an “elite” player.

“We have some players that haven’t played this series and are good players as well,” Hayes said. “They bring a lot to this team. It’s an up-next mentality” if Couturier can’t play.

Couturier “does everything for our team. First power play, first PK, takes a lot of draws for us,” Laughton said. “Obviously you’re not going to fill the shoes of a player like that. I think you have to do it by committee and everyone has to step up and try to do the same job to make up for it. We’ll see what happens here in the next day.”

If Laughton has to play on the top line (with Giroux and Jake Voracek) instead of the third unit, “I don’t think it changes much. I have to play the same way,” he said.

On Tuesday, Laughton played most of the first two periods centering James van Riemsdyk (goal) and Travis Konecny (two assists), each of whom had his best performance of the postseason.

“Two really highly skilled guys,” Laughton said of Konecny and van Riemsdyk, so “nothing really changes for me. Try to skate and create space for these guys. Try to get to the front of the net. At the same time, I’ve got to be good in our own zone and picking up guys and things like that. Something I will watch on tape and try to continue to get better at.”

Trotz said the Islanders and Flyers are “two evenly matched teams when I go through chances and we do all the analytics. It’s dead-even in a lot of ways, so we just have to raise our game to the next level. We have to get better starts. We’ve been chasing the last couple of games.”

Vigneault said the Islanders don’t have any weaknesses and wondered how many teams have players like Jean-Gabriel Pageau and Derick Brassard on their third lines.

“It’s just a real solid team, from the forward group, to their D group, to both of their goaltenders,” he said.

Vigneault, who had two of his Rangers teams overcome 3-1 series deficits (one against Trotz’s Capitals), said the Flyers’ last two games have been “our best since we’ve been in the bubble.”

He acknowledged that you “have to play your best” to beat the Islanders. “I’ve really liked the way we’ve trended the last two games. And that makes me optimistic that we can continue on that rise up.”

Rise up or go home. At this stage of the series, there’s no in between.