In the NHL, the response is what matters after a loss.

That’s the focus of the Rangers, who were breezing through the first quarter of the season before losing three of their last four games, including a stunning collapse Wednesday night in a 6-1 loss to the Penguins at home, where they are 8-3-1.

The next test comes right away, with a matinee Friday in Philadelphia.

“All I know is when we left Pittsburgh [after the Rangers beat the Penguins, 5-2, on Monday night], all they were talking about was the importance of responding well and preparing themselves for the next game, and I think the same goes for us,” coach Alain Vigneault said.

It appears that Matt Puempel, who was claimed on waivers from Ottawa, will make his Rangers debut Friday.

Puempel, who played 13 games with the Senators this season, skated on the left side with Josh Jooris and Jesper Fast on the fourth line at Thursday’s practice. Oscar Lindberg was the spare. The defense appears to be the same, with Adam Clendening as a healthy scratch.

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It’s the first of four games between the Metropolitan Division rivals this season. The Flyers (9-9-3) also are coming off a loss on Wednesday, dropping a 4-2 decision to the Tampa Bay Lightning after leading 2-1 late in the third period.

Last season the Rangers played three of five games in the City of Brotherly Love and each one ended by the same 3-2 score via shootout (the Blueshirts won two of them). Henrik Lundqvist faced Flyers netminder Steve Mason in each game.

The Rangers are without two of their top nine forwards, as center Mika Zibanejad and left wing Pavel Buchnevich are injured. The Flyers lost center Sean Couturier to a leg injury on Tuesday and former Ranger defenseman Michael Del Zotto also might not play.

The Flyers are second in the NHL on the power play but 23rd on the penalty kill. The Rangers rank seventh on the power play and sixth on the penalty kill. The Blueshirts are 6-3-0 on the road; three of those wins came on the Western Canada trip.