Barry Trotz spoke strongly after Tuesday night’s loss that his team needed to have a playoff mentality.

Through one period Thursday, it looked as if the New York Islanders received the message loud and clear.

By the second, the message was lost in translation.

The Washington Capitals deposited their final goal of a 6-3 win over the Islanders in the dying minutes of the final period, but the game was over in the middle third.

Things looked good after one, as the Islanders built up a three-goal lead with two of the scores coming from the bottom-six forwards.

So what went wrong in the second frame?

A little bit of everything. In a span of 2:04 halfway through the period, the entire face of the game flipped.

“It’s a tough one because we didn’t play that poorly for probably 50 minutes of that game,” Trotz said Thursday. “[But] in the two-three minute span, we were just average, below-average — pucks went in.”

In quick succession, Conor Sheary scored twice, once off a rebound and another on a deflection. Less than a minute after the second, Garnet Hathaway beat Semyon Varlamov under the arm on a shot from the right circle that the Islanders netminder almost undoubtedly should have corralled.

The Islanders had far and away their worst period of the night by almost all measures, and Trotz said that quick barrage put the team in “stun” mode.

Whether it was being stunned or getting outplayed, the Islanders generated 17 shot attempts to the Capitals 23 during 5-on-5 play during the second, which changed the script and the score.

When you factor in the slashing penalty from Oliver Wahlstrom (which led to John Carlson’s game-winning goal), the Islanders recorded only 37.78 percent of the scoring chances in the second. The high danger department wasn’t any better, as Washington had three to the Islanders’ none.

By period’s end, Washington had rattled off five goals and seized control of the game for good.

“When those things happen you have to take a deep breath and calm yourself down,” Anders Lee said of the second. “We just a little bit on the wrong side of things too many shifts in a row there. The mentality is to get right back to our game.

The offense has been hard to come by for the Islanders being tied for second to last in goals per game at 2.00. You can pinpoint plenty of different periods so far this year where they’ve been outscored or out-shot. But purely from a shot generation and possession standpoint, the Islanders have been consistently poor in the second period.

Not once has the team produced a Corsi For percentage above 50 at 5-on-5 in the second in any of the seven games they’ve played this year, according to Natural Stat Trick. And with Tuesday’s effort, they’ve been outscored 9-2 in second periods so far.

“We’ve gotta keep getting to the net and making it hard on the other team’s goalie and defense,” Casey Cizikas said. “When we get away from that, that’s when it can get it ugly.”

Especially after the way they lost a winnable game against Washington on Tuesday, keeping up the pressure in the second could’ve made this an entirely different story. That pressure was there in the third with 95.45 percent of the shot attempts.

But with Washington pushing and the Islanders’ lack of answer, it led to another tough loss. For an experienced, veteran group, dealing with adversity and losses is nothing new. For things to get better, Trotz said, is to have a growth mindset and keep looking ahead rather than at past mistakes.

“We can’t look back, this ended up being a wasted two games here for us,” Trotz said. “All we can do is make good going forward. But there is an urgency level and I think there’s an urgency level through the whole division because the whole division is ultra-competitive.

“We’ve gotta stay in the fight.”