Islanders’ new-look top line excited to show what it can do

Here’s one thing you should know about Mat Barzal: He is a hockey fan.

That is to say, Barzal often watches games from around the league on off nights, rather than taking a break from everything. So, too, it turns out, does Anthony Duclair. And so does Bo Horvat.

That worked out pretty neatly as the trio worked through training camp and the preseason as linemates trying to build chemistry in advance of Duclair’s Islanders debut on opening night Thursday against Utah.

“I think every single day we get to the rink, we’re always talking about new plays,” Duclair told The Post following Wednesday’s practice. “Watching other preseason games, watching the games last night, just talking. How to get better, how to improve, just finding each other on the ice. Just constant communication between us three.”

This was a somewhat rare situation in which everybody knew coming into camp — and really, since Duclair signed with the Islanders on July 1 — that he would pair up with Horvat and Barzal, who had considerable success in their first season together.

The whole point of signing Duclair in free agency was to complete a top line, as no one had stuck alongside the two for most of last season.

Duclair — a fast, offensively skilled player who has reached the 30-goal mark before — looked like a fit, though he’s never averaged more than 16:16 of ice time per night. The (very) early returns have backed up that thesis.

The top line was excellent in the preseason, frequently dominating puck possession, outsourcing opposition 4-0 and producing a 24-13 scoring chance disparity, per Natural Stat Trick.

Four preseason games should be taken with the smallest possible grain of salt, but it’s encouraging nonetheless, especially when Barzal’s unique style has taken others some time to get used to in the past.

“Playing against this guy, every time, he seems like he’s got the puck on his stick the whole game,” Duclair said. “He’s a big puck possession guy, loves to handle the puck, loves to make plays. I love to play with a guy like that, a guy that can see the ice so well. Obviously his speed, too, we can [both bring] speed, put opposing defensemen on their heels. I think we complement each other very well.”

It is Duclair’s 11th season since breaking in with the Rangers, when he played 18 games on Broadway as a 19-year-old.

He has not been with one team for longer than three seasons, but signed with the Islanders for four.

If the regular season looks anything like the preseason, he will be The Duke of Long Island in short order.

Barzal thinks they can look even better.

“I actually think there’s more for us to create,” Barzal said after the preseason finale, a 5-2 win over the varsity Rangers squad in which the three players on the top line accounted for a combined four goals and six assists. “As much as the puck’s gone in the net, that’s one thing. The actual quality, I think, is almost there. I think holding the puck in the O zone and whatnot, we can be better.”

That would be something like a dream for a franchise that’s been waiting a long time for a top line with this kind of firepower.

The waiting, at least on that score, just might be over.

The Islanders have spun their wheels in first-round playoff exits for the last two seasons.

Duclair — and the top line he completes — is a reason to think they can drive their way out of the muck.

“Very excited,” Duclair said. “Excited to get going. I thought it was a really good training camp all around. Guys worked hard, getting to know all the guys, the locker room, just finding myself around the Island. Finally all the hard work has paid off here.”