How David Quinn addressed Tony DeAngelo’s ‘maturity issue’

So another teaching moment for another young Ranger denied a uniform for a divisional rivalry game. Say what you will about David Quinn, but this is a coach who addresses issues on the spot rather than sloughing them off for a later day.

Two nights after Pavel Buchnevich sat against the Flyers, Tony DeAngelo was designated as the healthy scratch on the blue line for the Blueshirts in Thursday’s 4-3 victory over the Devils in Newark. This was not a performance-related decision. DeAngelo, in fact, had played the most consistently structured and productive hockey of his short tenure on Broadway over the previous six games during which he had been elevated to the first pair as Marc Staal’s righty partner.

But something occurred early in the second period of Tuesday’s 1-0 defeat to the Flyers that prompted the first-year coach to sit DeAngelo for a long stretch before going back to No. 77 for his regular shifts during the third. Again, it was not a bad read, an inexplicable giveaway, an undisciplined penalty or anything that would have been noticeable by reviewing the video. It was something else, something behavioral that crossed a line.

“It was a maturity issue,” Quinn told The Post. “He and I have talked about it and are working on it. He’s too good to let maturity issues get in the way of him becoming the kind of player that he can be.

“It’s something he’s got to work on and it’s something we’ve got to help him with.”

And so DeAngelo sat and watched in street clothes while Mika Zibanejad recorded a hat trick, Mats Zuccarello racked up three assists and Henrik Lundqvist responded with several late, big-time stops to seal his club’s fifth victory over the past seven games after having won five of the previous 21 (5-11-5).

Tuesday, in sitting Buchnevich, Quinn dressed a clearly inferior lineup that featured seven defensemen. That did not stop Quinn from doing what he believed necessary to catch No. 89’s attention. That also did not prevent the Blueshirts from piling up a 38-19 edge in shots (and a 62.3 percent Corsi at five-on-five) but the fact is that they could not score and were shut out by Anthony Stolarz.

Thursday, in sitting DeAngelo, the coach broke up the tandem that had been the club’s most effective first-pair while going back to the Staal-Neal Pionk duo that has had its challenges pretty much from the get-go. Over their six games intact, Staal-DeAngelo recorded a 58.0 Corsi share, a 57.5 shot share and a plus-two rating in 78:49 of five-on-five play. In the six games prior to that, Staal-Pionk came in at a 41.0 Corsi, a 41.1 shot share and a minus-four in 74:43, per Naturalstattrick.com.

What’s more, prior to Thursday’s reasonably sturdy work, the Staal-Pionk pair had the worst Corsi rating — 41.2 — in the NHL of any tandem that had played at least 500 minutes, per Corsica.Hockey. Yet, Quinn reunited No.’s 18 and 44 because there was a lesson to be taught No. 77. And by the way, that did not stop the Rangers from dominating at five-on-five in this one.

Zuccarello, who missed Tuesday’s game with a foot infection, has 12 points (4-8) in his last six games. Still, despite his revival (or perhaps because of it), he is almost certain to be elsewhere following the Feb. 25 trade deadline, though the prospect of a summer return via free agency somehow doesn’t seem wholly out of the question. Kevin Hayes, despite another strong game, is likely to be dealt as a rental property, too. Both pending free agents have made it clear they wish to remain Rangers. Ultimately, absent trade protection, they have no say in the matter.

Staal, though, does have say if a contender is interested in dealing for the 32-year-old,who would be a catch as a depth defenseman as the alternate captain has a full no-move clause in the contract that carries a $5.7 million cap hit through 2020-21. Get this about Staal: He has been charged with the responsibility of playing first-pair against the opposition’s top guns on a nightly basis for the first time since 2010-11, before the unbrotherly concussion he suffered as a result of that high hit in Carolina from Eric Staal. Just try to find another defenseman to go eight years between first-pair assignments in the NHL.

“I don’t know what I would do if I were asked to waive,” Staal told The Post this week. “It really hasn’t crossed my mind at this point. Hypotheticals are tough.”

Not nearly as tough, though, as sitting out a game for reasons other than performance. Nothing hypothetical about that, as DeAngelo was reminded yet again.