It has gone so well that, when Charlie McAvoy was out with an injury in November, Zadorov was rewarded with the “A” of an alternate captain, perhaps the truest sign that any rockiness in the transition has been smoothed out.

“It took time,” the 30-year-old Zadorov said. “Sometimes I’m coming in a little bit too hot at the start, especially with relationships, you need to build that relationship. And the hockey part helps. I feel like the tightest teams I’ve been to, that’s when you know everybody has their backs. When you go on the ice, you go like a war, and then you have your brother beside you. So I feel like that helps a lot.”

That’s where the understanding is born, where the trust develops – the hits, the blocked shots, the fights, the right words at the right time in the room.

But none of that happened immediately. There were stumbles.

“I think last year that was definitely part of what I experienced with him was trying to understand him, trying not to take things the wrong way in that regard when he was maybe overly honest or blunt in how he approaches things,” McAvoy said. “I think maybe here the way that we say things or bring things to people’s attention might be different, maybe a little softer.

“But that was something that I learned with him was, and honestly some of the Europeans in general that I’ve gotten to play with at this point, it’s like they don’t mean anything bad by it. But I think they’re a little bit more honest than we are.”

It’s a difference in approach, in culture, that he’s seen not just with Zadorov, a Moscow native. As McAvoy said, “I think I forget a lot of times how far from home those guys are and that they’re learning another culture and stuff and that must weigh on them.”

“Everybody makes mistakes,” Zadorov said. “Sometimes I get emotional on the ice. I bark on somebody and I’ll be like, ‘Hey man, I’m sorry, I didn’t mean to, I just care.’ You know what I mean? … The guys know, too, like sometimes I come a little harsh because in Russian language and Slavic language, we are like that. We’re just pretty direct and we’re less polite like you Americans. We don’t poke around, we just got straight to [the point].”

It wasn’t just in the room. It took time for him to find himself on the ice, too, even if he knew when signing that the fit would ultimately be ideal. He had, after all, played against the Bruins in the second game of his NHL career, a game that featured a Boston roster with Zdeno Chara, Milan Lucic and Shawn Thornton. That image stuck.

“It was a tough team,” he said. “You’d go out there and you’d be like, ‘I’m going to get my [behind] kicked,’ so that’s the mentality. Yeah, it’s a really intelligent and smart city, but our fans are blue collar at the end of the day. They come after work, they want to open Bud Lite, they want to watch the game, they want to watch fighting, you know what I mean?

“They love this stuff and it fits me perfectly.”

His tenure, though, began with too many penalty minutes accrued and some uneven play — he leads the NHL in penalty minutes with 113 this season and finished first in the category last season with 145 — on a team that saw a coach fired and a new direction forged in 2024-25. But this season, the defenseman has rounded into form, with Zadorov finding chemistry with McAvoy and becoming part of the Bruins top defense pair, at least when everyone is healthy.

He has shown off the best of his game, gaining consistency, unearthing the promise that once led Ted Nolan, his first NHL coach with the Buffalo Sabres, to tell him that he would someday win the Norris Trophy as the best defenseman in the League.

Nolan recalled recently discovering Zadorov, even at 18 and 19, as a “good-sized kid who could skate,” praising both his hockey IQ and the mindset that “he knew he was good and he was going to prove that he was.”

It took a couple of stops to do so, with a trade that sent him from Buffalo to the Colorado Avalanche for five seasons, a brief stop with the Chicago Blackhawks, two-plus years in Calgary and a half-season in Vancouver before signing with the Bruins, propelled by the 2024 Stanley Cup Playoffs run with the Canucks that saw him have eight points (four goals, four assists) in 13 games.

“I think you saw him kind of scratch the surface there in Vancouver on the playoff run and you could see what kind of defenseman he could be,” said Lindholm, who was also acquired by the Canucks in a separate trade from Calgary during the 2023-24 season before both Lindholm and Zadorov signed with the Bruins in the summer of 2024. “Playing like [he is] right now, he’s really hard to play against. … You’ve got to know when he’s out there for sure. He can come from anywhere and he’s pretty big.”

That goes for his size, at 6-foot-7 and 255 pounds. His hits. His approach to life, which he appears to grasp with both hands.

It was Zadorov, after all, who walked into TD Garden on Dec. 23 in a full Santa Claus suit, before a game against the Montreal Canadiens in which he would be trading punches with Arber Xhekaj by the end of the first period.