Lindgren knocked out; Ruhwedel in

The Rangers are holding their breath about Ryan Lindgren yet again.

Over the last few years, the Blueshirts have become accustomed to watching Lindgren take what seems like a terrible hit only to pop back up and be just fine. But when he went down in the left corner after a hit from Jean-Gabriel Pageau during the second period of Sunday’s 5-2 win over the Islanders, there was no instant reprieve.

RANGERS & ISLES NOTES

Instead, Lindgren — without putting weight on his left leg — was helped to the dressing room and did not return for the third period.

“He’s lower body,” coach Peter Laviolette said postgame. “He’s getting evaluated right now.”

For the Rangers, who are already missing Jacob Trouba on the right side of their defense with a lower-body injury, that is far from an ideal situation. Lindgren, despite his bruising game, has missed just two games this season.

“Obviously that’s tough,” Will Cuylle said. “He’s a pretty tough guy, plays through a lot of injuries all the time. Don’t like to see him go down. Hope he’s good.”

If he isn’t ready in time for Tuesday’s clash against Winnipeg, it will likely mean Chad Ruhwedel will be inserted into the lineup for his debut on Broadway after the Rangers acquired the right-handed defenseman as depth at the trade deadline, sending a 2027 fourth-round pick to Pittsburgh in return.

“We have Rudy back there. Solid defender,” Vincent Trocheck told The Post’s Larry Brooks. “Hard to play against. Played against him for a long time. He’s another guy that can come in, seamlessly make that transition.”

➤ Islanders coach Patrick Roy kept Kyle Palmieri on the top line and Mat Barzal on the second line after switching the two in the third period of Saturday’s loss to the Senators.

He also switched his D-pairs to start the game before ultimately landing on the same configuration the Islanders have regularly used, with Adam Pelech paired with Noah Dobson while Alexander Romanov skates with Ryan Pulock.