Islanders head coach Barry Trotz on the bench during the...

Islanders head coach Barry Trotz on the bench during the third period of Game 1 of the Eastern Conference quarterfinals against the Penguins on April 10, 2019 at NYCB Live's Nassau Coliseum. Credit: Newsday/William Perlman

When Islanders coach Barry Trotz was asked Friday morning what role momentum plays in NHL playoff series, he did not hesitate, saying:

“Zero. Zero-point-zero, if there’s anything less than zero. Every game is its own entity. Once it’s over, you don’t look back. You have to look forward.”

Nine hours later, Game 2 of the Islanders’ second-round series against the Penguins began at NYCB Live’s Nassau Coliseum, and the home team picked up where it left off in its 4-3 overtime victory in Game 1.

If it could not be attributed to momentum, then perhaps it just meant the Islanders — win or lose — are more than capable of holding their own against the Penguins, a star-filled team that won Stanley Cups in 2016 and ’17.

In Game 2, they spent the first period taking the play to the Pens, outhitting and outskating them in a session that was chippy and disjointed — in other words, far more the Islanders’ style than the Penguins’.

Then things got even more chippy in the second, a nasty period that ended with the teams tied at 1 after goals by the Penguins’ Erik Gudbranson and the Isles’ Anthony Beauvillier.

Immediately after Beauvillier’s goal, Mathew Barzal, who assisted on it, went after the Pens’ Marcus Pettersson, and continued jawing at him while both sat in the penalty box.

So the series already is turning out to be as entertaining as many had anticipated.

But the Islanders are taking it as it comes, on Trotz’s insistence, which was why between Games 1 and 2, everyone involved took pains to remind anyone who asked — and perhaps themselves — that in the Stanley Cup playoffs, one game is but a blip.

That is what one would expect a coach to say, of course. But in this case, Trotz’s one-shift-at-a-time approach goes beyond mere platitudes. It is based on real-life lessons.

In theory, the Penguins entered with a gaping edge in playoff poise and savvy, with the core of their team having been together for years.

But Trotz and two of his assistants, Lane Lambert and Mitch Korn, were winning a Cup of their own with the Capitals only 10 months ago, a run that began with two home losses to the Blue Jackets.

“I think Barry’s obviously been in probably every situation in his 20, 30 years of coaching,” Barzal said before Friday’s game. “There’s no situation he doesn’t know how to handle, and having that kind of experience behind the bench for sure helps.”

Friday night was Trotz’s 115th NHL playoff game as a head coach.

How often does he bring up that Cup run — which included a second-round elimination of the Penguins — when talking to his team, and how often do they ask him about it?

“I think those have been lessons all year,” he said. “I always say, ‘This is what I’ve experienced, this is what I can tell you, and this is what’s going to happen,’ just through experience. They listen, but you have to live it.

“This is no different than your parents saying, ‘Don’t touch the stove’ when you’re young. You keep touching the stove and then you burn yourself and they go, ‘I told you so.’ They’re very good at listening and comprehending, but you still have to live it. You’ve got to do it.”

The Islanders do have five players who have lifted the Cup for other teams: Johnny Boychuk, Nick Leddy, Valtteri Filppula, Tom Kuhnhackl and Andrew Ladd (who is injured).

“[The coaches] have it fresh in their minds from last year,” Jordan Eberle said. “There’s a lot of wisdom. The way they talk, I think everyone soaks it up pretty good. Having the experience, you listen a little bit more.

“But you look at our team, we’re not a young team. We have a lot of guys who have won Cups and been through runs in the playoffs. This isn’t really different territory for a lot of guys.”

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