BOSTON - The change of address is obvious. The same seems true of the change in role, but Jaroslav Halak isn’t so sure about committing to that.

“It’s a long season,” Halak said on Monday, a day after the Bruins signed the 33-year-old goalie to a two-year contract. “I’ve seen it in the past. We’ll find out.”

Halak, speaking to a pool reporter, likely wasn’t suggesting he thinks he’ll climb over No. 1 goalie Tuukka Rask on the depth chart. The B’s signed Halak, after all, only because Anton Khudobin accepted a two-year offer from the Stars on Sunday after two years as Rask’s backup.

Halak has tended goal in the NHL long enough to know, however, that sometimes backups end up being No. 1, or No. 1A, whether because of injury, performance or any number of other reasons.

Over 10 full NHL seasons with three teams (Canadiens, Blues, Islanders), Halak has been a backup who has taken away a No. 1 job, a No. 1 who has lost the job to a backup, an award winner (he and Brian Elliott shared the William Jennings Trophy, presented to the team that surrenders the fewest goals, with the Blues in 2011-12), and in no-win situations like last season, when he posted some of the poorest numbers of his career (20-26-6, 3.19, .908) as the often-defenseless No. 1 goalie of the league’s worst defensive team: The Islanders were last in the NHL in goals-against average (3.57), last in penalty-killing (73.2 percent) and allowed more shots per game than any team (35.6).

It’s not hard to understand, then, why Halak would consider a reduced role and the corresponding reduction in salary — $2.75 million for the next two seasons, after a four-year deal with a $4.5 million salary cap hit as an Islander. The Bruins ranked fourth in the NHL in goals-against average (2.57), third in penalty-killing (83.7 percent), and Rask and Khudobin faced only 29.3 shots per game — No. 2 in the league.

“They have a great team, a lot of talent,” Halak said. “They’re always on top of the standings. I’ll try to help out any way I can.”

While the Bruins spoke with Khudobin about returning, praised his performance (16-6-7, 2.56 GAA, .913 saves percentage), and consistently spoke of the need for a proven, dependable goalie behind Rask, they seemed comfortable spending a little more on Halak, whose resume includes No. 1 assignments in Montreal (where he unseated No. 1 Carey Price in 2009-10) and St. Louis before he signed with the Isles.

“We looked at that signing from every angle,” Sweeney said on Sunday.

“Jaro’s carried the ball with other teams. He’s had months where he’s played 10 games. He’s had usually about 26 starts (49 last year, the fifth straight with at least 26). That fits into what we’re trying to expect … what the goaltender tandem needs going forward.”

While Rask’s year-over-year goals-against average rose (2.36, from 2.23) and his saves percentage was essentially flat (.917, from .915) last year, his starts were reduced significantly from 64 to 53, and he still won 34 games.

“We backed off Tuukka’s games last year, and it worked very well,” Sweeney said.

“Two years ago, we didn’t have a win by our backup goalie (Khudobin, who suffered an early hand injury, plus Zane McIntyre and Malcolm Subban) at Christmas time. … I lost sleep about it. There were nights (in 2016-17, when Khudobin missed part of the season with a hand injury) when Tuukka played back-to-backs. That’s a lot of stress on the goaltender.”

Sweeney thinks Halak can do “an equal, if not a better job” than Khudobin at keeping Rask’s schedule reasonable. Halak will try to do as much as he can with the opportunity.

“I’ll try to fit in as soon as possible,” Halak said. “I’m looking forward to being with (Rask). I know he’s an elite goalie, and he proves that every year. Every time I get the chance, I’ll try to help out, and we’ll see what happens.”