Rangers' Antti Raanta proves himself while filling in for Henrik Lundqvist

In the absence of Henrik Lundqvist, Antti Raanta did all that can be expected from a backup.

The Finnish netminder, who has stepped in for Lundqvist in the last seven games while the Swede recovered from a hip strain, has kept the Rangers afloat.

But with Lundqvist expected to reassume the No. 1 role this weekend in California, Raanta, 27, will return to playing second fiddle, ready to jump back in when needed.

In the seven games before last night’s 3-2 Rangers loss, Raanta was 3-2-2, with a 2.23 GAA, a .920 save percentage and a shutout. And in 24 starts before last night, he was 15-5-2, with a 2.19 GAA, and a .926 save percentage.

“He’s been solid, he’s an amazing goaltender,” Derek Stepan said. “I compare him very similarly to Cam Talbot. He did the same thing, put solid games together for us.”

But Raanta and his teammates couldn’t stop the Islanders in the third period, as they overcame a 2-1 deficit with two power-play goals — the first which bounced off two Islanders’ skates, and sent the Blueshirts to their seventh straight loss at home.

“It’s part of the riddle here at home,” Stepan said. “Our special teams, if you look at the numbers, are crazy compared to the road. On the PK tonight, we had some bad bounces. We scored one power play goal but should’ve had more. The pressure to win at home shouldn’t be there, and we’ve allowed it to get there.”

To be fair, the schedule hasn’t been favorable for Raanta, who had appeared in 21 games before Lundqvist was injured on March 7: Three back-to-back sets. In general, goaltenders split those duties.

The run started with a 4-3 loss in Carolina, where the Rangers allowed two goals on four power plays, and then a 4-1 win at Joe Louis Arena in Detroit, before a next-day 3-2 loss to Tampa Bay at home. Raanta allowed just one goal in the shootout in a 4-3 loss to the Panthers, then went on the road and backstopped a 3-2 win in Minnesota, one of the best teams in the West.

Last night’s game followed a 3-2 overtime loss in New Jersey on Tuesday. Raanta has kept them in every game.

“We were the better team on the ice tonight, but when the luck is not on your side,” said Raanta, who arrived from the Chicago Blackhawks in a swap for Ryan Haggerty in June 2015.

Raanta has reached career highs in appearances (29), wins (15) and shutouts (3). “And when you don’t have the confidence right now in your own building, we just have to work extra hard,” he said. “It’s really frustrating.”

What’s next for Raanta? Well, short-term, he will be available to spell Lundqvist. And in the summer, there’s a possibility he could very well be moving on. Teams can protect only one goaltender in the expansion draft and Lundqvist isn’t going anywhere.

At 27, though, and with a very favorable one-year contract worth $1 million next season, he could be too tantalizing for the Vegas Golden Knights to ignore.