PITTSBURGH — Two games below NHL .500 after a listless performance in Pittsburgh, unable to string together multiple wins and the head coach questioning his team’s mental toughness in public.

That is the state of play for the Islanders after Sunday’s sluggish and discouraging 3-2 loss to the Penguins at PPG Paints Arena in which they lacked detail and execution a mere 22 hours after dominating the same team on Long Island, setting back all the progress of that 6-3 win and blowing a shot to get within a point of the playoff cutline.

Don’t let the final score fool you after a pair of Anders Lee goals at six-on-five made for a tight finish.

Patrick Roy didn’t.

“I just felt like after we gave up that second goal, we were not mentally strong enough,” Roy said. “It’s just a goal. We were down two — two goals is nothing in this league. We proved it.

“With seven minutes [left], we pull the goalie, we score one, five minutes, we score another. You could come back in those games. And sometimes, I feel we don’t believe enough in that.”

Even for a head coach as brutally honest as Roy, those words sting.

They are not, however, easily disproved about a team that has come back to win just once in the third period this season and which now sits at 14-16-7 — a three-game winning streak away from becoming a factor in the East’s wild-card race, but without any such streak through the season’s first 37 games.

Actually, they’ve managed to win consecutive games just twice.

“Right now, this win one, lose one thing is not gonna do us any favors here going forward,” Bo Horvat said. “For the rest of the year, if we’re gonna continue to do this, we’re not gonna move up the standings. It’s on us in here to get the ball rolling.”

A brutal second period in which the Islanders went scoreless on two power plays while compiling just four shots at five-on-five encapsulated the night, with Roy shifting his lines around to try to create some kind of spark.

“We were not satisfied with our puck management, our dumps,” Jean-Gabriel Pageau told The Post. “We had too many turnovers at their blue [line]. That’s what they fed off.”

That — and the Islanders’ awful penalty kill, which let up a pair of goals to Michael Bunting and Evgeni Malkin to allow Pittsburgh to stretch their lead to 3-0.

The Islanders have now allowed 15 goals in their past 14 at four-on-five, and remain on pace to be the worst penalty kill since the stats have been kept starting in 1977-78.

Though the Isles mounted a push, with Lee scoring twice at six-on-five to make for some drama, nobody was pretending that was enough.

“I didn’t think we competed like we were capable of yesterday,” Roy said. “We were quick on those loose pucks, we were sharp, we executed better than what we did today for some reason. And we were more at the net as well.

“If you want to score goals at five-on-five, if you want to score on your shot, you better be a good shooter. If not, you’re gonna have to drive the net and find ways to get those rebounds like we did last game.”

If there was a silver lining to be had, it was Marcus Hogberg’s performance in his first start in goal.

The Swede stopped 37 shots and wasn’t at fault for any of the three he let in, with the Islanders giving little help to a netminder who had not started an NHL game in nearly four years.

Old friend Anthony Beauvillier was allowed to get free at the backdoor off the rush 3:54 into the match for the Pens’ lone five-on-five goal, and the other two came on the power play, with Hogberg having little chance on either.

“I thought he was outstanding,” Roy said of Hogberg. “I don’t think we played well in front of him.”

The state of the East means that as poor as their record is, the Islanders are still lurking on the periphery of the race, still a winning streak away from becoming a real factor.

The state of the Islanders means there is not much reason to think such a streak is imminent.