New York Islanders left wing Anthony Duclair is down on...

New York Islanders left wing Anthony Duclair is down on the ice in the third period against the Montreal Canadiens at UBS Arena on Saturday. Credit: Kathleen Malone-Van Dyke

The full extent of the damage to Anthony Duclair’s right leg won’t be known until Tuesday after further X-rays and MRIs. But Islanders president and general manager Lou Lamoriello acknowledged that the top-line left wing will be sidelined “more long term than short term at this point.”

“Certainly not season-ending,” Lamoriello said before the Islanders’ practice on Monday at Northwell Health Ice Center in East Meadow.

It’s a small something. Still, the Islanders, who will face the Red Wings on Tuesday night at UBS Arena, again need to find a complementary piece for Bo Horvat’s trio with Mathew Barzal after signing Duclair as a free agent to fill that role.

“It’s tough,” said Horvat, who’s played with a long list of rotating wings since being acquired from the Canucks on Jan. 30, 2023. “You’re just trying to start to find chemistry. It’s a big loss for us, but other guys have to step up and fill that void.”

Based on Monday’s practice, Simon Holmstrom likely will get the first chance to skate with Horvat and Barzal, with Casey Cizikas likely being elevated from the fourth line to take Holmstrom’s spot on Jean-Gabriel Pageau’s third line with Anders Lee.

“I played with Barzy and Bo a little last year,” said Holmstrom, who finished Saturday night’s 4-3, nine-round shootout win over the visiting Canadiens on the top line after Duclair was injured. “That definitely helps.”

Lamoriello said a forward will be recalled from the Islanders’ AHL affiliate in Bridgeport, but it had yet to be determined whether Duclair will be placed on injured reserve or long-term injured reserve. The latter would give the Islanders more salary-cap flexibility but hurt their ability to accrue cap space before the March 7 trade deadline.

Actually, two forwards could be recalled, with speedy right wing Julien Gauthier clearing waivers on Monday and being reassigned to Bridgeport.

Pierre Engvall, who had a poor training camp but still was a surprise demotion in the second season of a seven-year, $21 million deal, is a possibility. So is Hudson Fasching, also sent to Bridgeport after training camp.

But Lamoriello said signing longtime fourth-liner Matt Martin — still practicing with the Islanders on a professional tryout offer — is not a consideration.

Duclair, 29, signed to a four-year, $14 million deal, was injured early in the third period while trying to split two defenders on a rush deep in the Canadiens’ zone. He went down awkwardly with his leg twisted underneath and was helped off the ice by Horvat, unable to put weight on his right leg.

Duclair, who is playing for his ninth NHL franchise in 11 seasons, had two goals and an assist in his first five games with the Islanders.

“We don’t like those injuries, especially one that could be long,” Islanders coach Patrick Roy said. “It’s always tough to lose a player like that.”

Notes & quotes: Roy said that goaltender Ilya Sorokin will start against the Red Wings ... Gauthier logged a team-low 7:42 against the Canadiens in his season debut after four healthy scratches. “I just expect more from him,” Roy said. “I was not comfortable putting him in at the end of the game. I guess that tells you everything.” Added Lamoriello: “Getting him into that game just showed that he needs to get in game situations. So we’ll get him to the minors.”