Nicknames are a foundational aspect of hockey culture, and there weren’t many better than a mountain of a man named “Moose” roaming around the ice and scoring for a team at the base of the Front Range.

But that wasn’t who Mikko Rantanen was in the Colorado Avalanche locker room. He was Mikko.

Not every hockey nickname sticks inside the dressing room. Sure, Erik Johnson is EJ. Devon Toews is Tazer. But Nathan MacKinnon is Nate, not Nate Dogg or The Dogg. Cale Makar is just Cale. And Mikko Rantanen was Mikko.

That’s a hard thing to shake. Rantanen is skating with the enemy now. He’s going to play for arguably Colorado’s biggest rival for eight years to come after this.

He nearly ripped the Avs’ hearts out Thursday night with a vintage Game 6 performance. And yet, when the Avs talk about members of the Stars, it is Seguin, Hintz, Heiskanen, Oettinger … and Mikko.

There’s a difference. It’s meaningful. It comes from years together, and the incredible success they shared.

Even as the Avalanche and Stars prepared for a Game 7 that had the potential to bolster legacies on both sides, at the end of an incredible seven-game war that more than lived up to the hype, the connection remained.

When does he stop being Mikko? When does he become Rantanen, or even “96” in coach speak?

“Every time the pads go on,” Avs coach Jared Bednar said. “That’s it. Every other time he’s going to be Mikko to me.”

A portion of the Avalanche fan base has already made that transition. Or, at least they’re voicing it at Ball Arena. Mikko was cheered during and after an emotional tribute video his first time back. Rantanen has been booed anytime he handles the puck for more than a split-second during Avs home games. He received a hearty level of displeasure after scoring the go-ahead goal Thursday night late in the second period.

He might still be Mikko to those fans if he had signed with Carolina after the trade, or chose … just about anywhere else but Dallas. Players and coaches understand the business side of this sport, though.

That bond was forged through nearly a decade of success and failure. It was cemented for eternity in 2022.

“You’re never going to hear me say a bad word about Mikko Rantanen,” Bednar continued. “You look at what he did for us the length of time I was here and he was part of the 2022 championship team. You’re just never going to hear me say anything bad about him.

“Look at the night he has (Thursday) night. Biggest stage, elimination game — he comes out and gets four points in a period and almost puts us away. We were able to bounce back, but that’s the way I view Mikko.”

This is not the first time the title winners in the Avalanche dressing room have had to face someone from that group in the postseason. Colorado played against Andre Burakovsky with Seattle in 2023.

He was Burky in the Colorado locker room. He was still Burky when he was down the hall with the Kraken.

When the Avs play the Calgary Flames, the guy who wears No. 91 is still Naz. Before he returned to the Avs at the trade deadline, Erik Johnson was still EJ in Buffalo and Philadelphia.

On Saturday night, the Avalanche searched for any lane available to get past Rantanen, the same stone-cold playoff killer they’ve always known. The guy who led the Stars with eight points through the first six games.

“You try to hold their best players in check. They’re the best players in the world, for a reason,” Toews said. “Mikko is up there with the best of them. You expect them to break out and get their opportunities at times. It’s just on us to try to slow them down as a group of five on the ice. (Thursday) night wasn’t the best job we’ve done against them. They were able to get a few last night, and our job is to shut them down for Game 7.”

Regardless of the outcome, when the dust settled from this titanic series, No. 96 in green became Mikko again.