LOS ANGELES — There’s no way to look at the Rangers’ recent penalty-killing except as a glass — well, perhaps a wine glass in California — half empty.

Playing shorthanded has really cost them, and not just the two power-play goals they allowed in the third period that lifted the Islanders to a 3-2 win on Wednesday night.

During the last seven games, the Rangers, who hold the first wild card in the Eastern Conference, have been shorthanded 22 times and have surrendered nine goals, a shocking 40.9 percent. The worst special-team units in the league during the season give up man-advantage goals about 26 percent of the time. And the Blueshirts have allowed at least one power-play goal in each of the last eight games.

Having lost two straight in their quest to whittle down their magic number for a playoff berth, which remained at seven entering Thursday, the Rangers know they must find a way to improve the penalty kill with eight games remaining.

“Bad bounces, it doesn’t matter. You’ve got to continue to work, try to take away those [shooting] lanes,” said Ryan McDonagh, who — along with Marc Staal and Jesper Fast — was on ice for each of the Islanders’ power-play goals. “Obviously, in front of the net, it seems to be where the puck’s going to end up. We talked about trying to collapse more with all four guys and making sure we don’t let them get second and third opportunities.’’

The penalty kill has skidded to 21st in the NHL, ranked 25th at home and eighth on the road. But the Kings, who will host the Blueshirts tomorrow night, rank fourth at home on the power play. Anaheim and San Jose, the next stops, are 15th and 19th at home, respectively.

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“A few weeks ago, we were talking about our power play and told you that we were working at it and sooner or later, it was going to turn the corner,” coach Alain Vigneault said. “It has, and I believe the same thing for our penalty-killing. We’ve got the personnel to get the job done and we will.”

Actually, they haven’t had all the personnel. Vigneault is fond of saying that “your best penalty-killer is the goalie.” Henrik Lundqvist is scheduled to play two games on the trip, and Dan Girardi and Kevin Klein have been medically cleared to play.

Notes & quotes: The Rangers are 10-1 against the Pacific Division but haven’t played in California yet. All seven Pacific teams have visited New York and the Blueshirts have played in Western Canada and Arizona. The Kings are 20-13-2 at home, the Ducks 23-8-4 and the Sharks 23-10-4 . . . Goalie Magnus Hellberg was returned to Hartford.