VANCOUVER — The Washington Capitals have allowed at least one power-play goal in seven of their past eight games. So what is coach Barry Trotz seeing from his struggling penalty-kill unit?

“Can’t kill anything,” he said Thursday night after the Capitals lost to the Vancouver Canucks, 6-2.

“Just a lot of extra pucks, a lot of failed clears,” Trotz said. “When you’re spending a lot of time in your zone and they’re putting pucks there, they’re going to find the back of the net. That’s what’s happening. It starts a little bit with failed clears and, you know, we’ve just got to be better back there.”

Vancouver entered Thursday night’s game with one of the worst power plays in the NHL, scoring on just 10 percent of its opportunities. But the Canucks feasted on Washington’s penalty kill, scoring three goals on six power plays. Through 10 games, the Capitals entered Friday’s NHL action with the third-worst shorthanded unit in the league with a 73.3 percent penalty-kill percentage, and the team has allowed six power-play goals in its past three games.

“I don’t know. I wish I had an answer for you,” forward Jay Beagle said. “I really don’t know. We’re going to go through the tape, obviously, and try to figure it out. Structure-wise, I think it’s little reads. I think we can do better disrupting their breakout. …

“I think there’s other things that happened, but if I had to pinpoint one thing, I think I can do a better job at the neutral zone and make sure they’re not entering our zone so easy and with full possession and time.”

The unit had personnel changes after the offseason departures of forward Daniel Winnik and defenseman Karl Alzner, both of whom logged heavy shorthanded minutes last season. It also doesn’t help that defenseman Matt Niskanen is out of the lineup with a left hand injury; he’s typically one of the first over the boards on the penalty kill.

With Niskanen out, blueliners Brooks Orpik, John Carlson and Dmitry Orlov have the heaviest shorthanded burden, and they’re also the ones playing the most at even strength, making for some tired legs in both situations. It hasn’t helped that the Capitals have taken 46 minor penalties through 10 games, tied for fifth most in the league.

Alzner’s presence seems to be especially missed as so many of the power-play goals seem to be coming directly in front of the net, where Alzner would typically clear opposing players out of the crease. Winnik was Beagle’s partner on the top unit, and Washington has tried both Devante Smith-Pelly and Alex Chiasson in that role this season.

“There’s a lot of dirty goals — shots and pucks kind of bouncing the wrong way for us and right way for them,” Beagle said.

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