If a team hardly changes from one season to the next, does it get better or worse?

That experiment in today’s NHL will be put to the test with the Islanders, who essentially have the same team that made it to the second round of the playoffs last season before being swept by the Hurricanes. The only big missing piece from that team is starting goalie Robin Lehner, who left as a free agent after he was a finalist for the Vezina Trophy.

But Lou Lamoriello is still running the crew of freshly shaved faces, while Barry Trotz will be behind the bench for his second year. Any improvements will have to come from within.

Offense

It was a solid sophomore season for center Mat Barzal, who might not have put up the same numbers from his Calder Trophy-winning rookie season — down from 85 points to 62 — but still showed his immense talent. He should center a good top line with Anders Lee and Jordan Eberle. Brock Nelson got his six-year, $36 million deal this summer, and the club will look for him to be a steady second-line center, probably next to Josh Bailey.

Lamoriello added veteran center Derick Brassard on a one-year, $1.2 million deal, and he’s going to get a chance to revive a career that had him on three different teams last season and five since the Rangers traded him in the summer of 2016. Michael Dal Colle, the No. 5-overall pick from 2014, is looking to be more productive after a 28-game rookie season, while Cal Clutterbuck hopes to rebound from offseason back surgery while reuniting with his fabled line of Matt Martin and Casey Cizikas.

Defense

It’s a bit of a surprise that Nick Leddy remained on the roster for opening night, but there he is. The slick-skating lefty defenseman, who, at 28 years old and with a reasonable three years left on his contract at $5.5 million per, was the most logical to come up in trade talks for another top-six winger. Leddy again could end up next to 35-year-old veteran Johnny Boychuk, who is finally healthy, or impressive rookie Noah Dobson, who made the team after being the 12th-overall pick in 2018.

Devon Toews is settling into his first full season in the NHL after an impressive 48-game rookie season, and he had some chemistry with hulking righty Scott Mayfield. Adam Pelech and Ryan Pulock also remain as a dynamic combo that can play in all situations.

Goaltending

Such a huge strength for the Islanders last season with the two-headed monster of Robin Lehner and Thomas Greiss, it’s hard to tell what’s going to happen now that Lehner left in free agency and was replaced by Semyon Varlamov. It sure seemed as if Lehner wanted to return after he revived his personal and professional life, but he said Lamoriello gave him an ultimatum to sign, and by the time he came back, the deal was off the table.

Lamoriello then signed the 31-year-old Varlamov to a bloated four-year, $20 million deal, in part to mentor fellow Russian Ilya Sorokin once Sorokin comes over from the KHL, presumably at this time next year. Varlamov is coming off the worst statistical season of his career, but splitting time with Greiss and working with goalie whisperer Mitch Korn might help.

Coaching

A year ago, Barry Trotz was just removed from winning a Stanley Cup with the Capitals, so he brought a gravitas that was even greater than the regular shake-up of a new coach. But Trotz noticed this year’s training camp naturally didn’t have quite the same intensity, and the question with a new coach is always how long the message will remain fresh.

That will be the challenge for Trotz, whose defense-first system is demanding for every player. Trotz still has his respected right-hand man Lane Lambert as associate coach, while he added Jim Hiller from the Maple Leafs to replace Scott Gomez and hopefully revive a power play that finished last season ranked 29th in the league.

Most important offensive player

Mat Barzal. The Islanders lack elite-level talent besides the 22-year-old Barzal, so not only will they look for his line to do most of the heavy lifting at even strength, he is also the engine on the power play. Coming up on a contract year, will he still be OK with middling offensive numbers on a winning team?

Most important defensive player

Ryan Pulock. The big righty has taken strides to establishing himself as a top-four defenseman in the league, bordering on top pair. With a booming shot from the point and a physical presence at 6-foot-2, 220 pounds, the 24-year-old will be eating minutes in all situations.

Top rookie

Noah Dobson. The Islanders were ecstatic when Dobson fell to the them at No. 12 in the 2018 draft, and at 6-foot-3 and 185 pounds, the righty shot seems ready for the big stage.

Key coaching decision

If the Islanders give up a few more goals than they did last year — a natural regression with the change in goaltending and maybe not the same super-commitment to defense the players had in Barry Trotz’s first year — then the club will need to score more. How Trotz tries to find that offense in a forward group not overrun with high-end scorers could make or break the goal differential (and therefore, the win-loss record).

Prediction

With a rather wide-open Metropolitan Division (if not an entire Eastern Conference), it’s hard to think the Islanders will take a major step back. They might not win the division, but they will make the playoffs and could win a round.