The Avalanche dressing room is a melting pot of different cultures.

When young Russian-speaking players join the team, like backup goalie Ivan Prosvetov, a leader steps up to welcome him in Colorado: Valeri Nichushkin. It’s one example of how the soft-spoken star is a beloved Avs teammate.

“His leadership really shows when you get young Russian players in, like taking Prosvetov under his wing,” coach Jared Bednar said earlier this month. “You also see it just by the way he leads by example. His competitiveness every day in the gym and practice. … Always doing the right thing when nobody is watching. He’s one of the hardest workers we have. It’s showing up on the ice.”

Nichushkin — following his still-unexplained playoff absence in Seattle — seemed to turn the page over the first half of this NHL season. The 28-year-old winger played himself into the NHL All-Star conversation with 20 assists and 22 goals, including 13 on the power play.

Nichushkin had never looked better.

That led to a surprise Monday when the NHLPA announced that Nichushkin is out indefinitely in the player’s assistance program. Nichushkin said in an online statement his absence is to “address my issues and prevent any negative outcomes once and for all.” It bookends a tumultuous nine months for the Avalanche star.

“It takes a lot of guts to be able to do that,” Bednar told reporters Monday night in Montreal. “He’s struggling through a (hard) time right now and we wish him the best. We’re going to miss him, no question. But we’re there for him.”

Nichushkin deserves empathy for his public decision to seek help. That takes courage.

But it doesn’t erase a harsh reality: he has yet to fulfill the lofty expectations that come with a $49 million contract. Nichushkin signed with the Avalanche through the 2029-30 season after their Stanley Cup run. Will he prove to be a good investment for general manager Chris MacFarland?

“I don’t think Val is immature at all. I have no question on Val as a person or a player,” MacFarland said before the season opener in October. “We’re very excited to have him. He’s a very important player in our mix. He’s a top-six force that, when he’s on the top of (his) game, he’s a beast to handle. He’s a fixture in our lineup.”

Nichushkin left the team for “personal reasons” in Games 3 to 7 of their first-round playoff series against Seattle. It’s no coincidence the Kraken advanced. Nichushkin declined to explain why a severely intoxicated woman was found in his team hotel room.

Now, he’ll be gone for an undetermined number of games with the top-heavy Avalanche already lacking quality forward depth. Artturi Lehkonen hasn’t played since early November and remains out with an upper-body injury. Nichushkin’s absence strips another top-six winger from the lineup.

A best-case scenario? Nichushkin returns to the Avalanche sometime in February with a clean slate after settling his issues. He resumes playing at an elite level and helps lead Colorado on a long postseason run.

A worst-case scenario? Nichushkin is unable to return until March or April and the Avs languish without his dominant net-front presence. Colorado’s depth issues are once again exposed in the postseason and questions linger over his future with the team.

Avalanche 7, Senators 4

What happened: Colorado rallied from being down 4-2 midway through the game with five unanswered goals for an impressive win playing on the second of back-to-back nights.

What went right: A Mikko Rantanen deflection at the crease provided the Avalanche their opening goal. Jason Polin scored his first career NHL goal in the second to tie the game, 2-2. Rantanen potted another goal later in the period. Miles Wood knotted it up again, 3-3, with a breakaway snapshot to begin the third period. Sam Malinski’s wrister from the point was the game-winning goal. Logan O’Connor provided cushion scoring late in the period. Devon Toews closed it with an empty netter.

What went wrong: Drake Batherson scored on the power play to give Ottawa an early lead. The Senators scored three goals in the second period — Ridly Greig (twice) and Jake Sanderson — to go ahead 4-3. A Malinski goal was removed upon Ottawa’s video review for an offside call.

Between the pipes: Justus Annunen made 36 of 40 saves. He didn’t allow a goal in the third period. Ottawa’s Mads Sogaard stopped 27 of Colorado’s 33 shots on goal.

Injury report: Wood (illness) returned to the lineup after missing several games.

What’s next: The Avalanche (29-13-3) face the Boston Bruins, 5 p.m. Thursday at TD Garden.