The Islanders’ biggest obstacle in the playoff chase right now is not the Red Wings or Capitals, though they’ll need to clear both teams in the standings to get in.

Nor is it the Flyers, who appear to be putting enough distance between themselves and the Islanders to make third place in the Metropolitan Division a distant objective.

No, at this point in the season — 11 games remaining and the Islanders needing everything they can gather to mount a push — their biggest enemy appears to be themselves.

That is the only conclusion left after a disastrous and self-defeating performance in a 4-0 loss on Sunday against the Devils marked the ninth time in nine tries that the Islanders have failed to win on the second end of a back-to-back and what feels like the umpteenth this season that they have appeared to find momentum only to fall flat.

Even right after Saturday’s 6-3 win over the Jets in which everything fired on all cylinders, there was a veneer of caution in the Islanders’ dressing room.

Ilya Sorokin reacts after the Devils scored a goal during the Islanders' loss on Sunday.

Ilya Sorokin reacts after the Devils scored a goal during the Islanders’ loss on Sunday. Robert Sabo for the NY Post

It was not so much about the win but about figuring out a way to keep it going.

By now, the Islanders know themselves well enough to be aware that is their problem.

But that doesn’t mean they’ve found a way to fix it.

Sunday instead featured Lucy pulling away the football as the Islanders succumbed to their own mistakes and watched two points slip through their fingers on a day they very much could not afford for that to happen.

The wheels were loosened at the end of a first period in which the Isles failed to convert during 3:58 of power-play time and committed three consecutive penalties in the final 2:12.

Then they came off completely in a shambolic second which saw New Jersey score three goals in the first 6:12 and Isles captain Anders Lee get himself thrown out of the match courtesy of a dirty hit on Nico Hischier.

With 1:13 of five-on-three time carrying over from the first period, the Devils easily converted with Timo Meier deflecting in Jack Hughes’ pass to the right post.

The Islanders then put themselves front and center on the blooper reel as Kyle Palmieri, Bo Horvat and Noah Dobson collided in the offensive zone to give the Devils a two-on-one breakaway, which the elder Hughes easily converted.

A few minutes later, Lee lost a puck battle to rookie defenseman Simon Nemec, who easily slid it across the ice to Alexander Holtz to make it 3-0.

Before the period was over, Lee had made things worse by sticking his knee out to connect with Hischier’s, resulting in a game misconduct and a pair of five-minute majors, with Meier — who jumped in to fight the Isles’ captain — also picking up a fighting major and 10-minute misconduct for instigating.

The Islanders couldn't score against Devils goaltender Kaapo Kähkönen during their loss Sunday.

The Islanders couldn’t score against Devils goaltender Kaapo Kähkönen during their loss Sunday. Robert Sabo for the NY Post

Jack Hughes (86) and his Devils teammates celebrate a goal during a victory against the Islanders on Sunday.

Jack Hughes (86) and his Devils teammates celebrate a goal during a victory against the Islanders on Sunday. Robert Sabo for the NY Post

Chris Tierney added an empty-net goal for the Devils late in the third.

It all added up to one of the most spectacular meltdowns the Islanders have had on home ice all season, in yet another moment where they absolutely could not afford one.

Lee’s hit could also result in supplemental discipline from the league, which would further hurt the Islanders during a crucial three-game road trip that begins on Thursday against the Panthers.

Thanks to the resurgent Capitals beating Winnipeg, the Islanders are now four points out of a playoff spot with one fewer game left than Washington.

On the ice from Long Island

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They stayed three points behind Detroit, which did not play Sunday but ceded their game in hand without gaining ground.

In other words: the math does not favor them.

At this point, the reality is the Islanders are going to have to find something in the next 11 games that they haven’t all season, and it is not their ultimate potential.

Sustained excellence, over any span longer than a couple weeks, is what has eluded them all season — not a high-performance ceiling.

And it is what they are going to need now in order to make the playoffs.