The Bruins placed defenseman Hampus Lindholm on injured reserve and activated defenseman Henri Jokiharju off the IR ahead of Tuesday’s game against the Kraken in Seattle (10 p.m.).

The moves were expected after it was learned on Monday that Lindholm was going to miss some time, though the injury is thus far undisclosed. It is not exactly clear when he suffered the injury. He played 22:47, including a couple of shifts in overtime, in the B’s 3-2 OT win in Vancouver on Saturday.

On Monday, coach Marco Sturm told reporters in Seattle that “it’s not going to be a day-to-day thing.” That sounded ominous, but Sturm softened the prognosis before Tuesday’s game slightly.

“It’s not a big concern. It just has to get healed the right way,”  said Sturm, who said the injury did happen sometime in Saturday’s game. “It’s not going to be the next game (that he’ll be ready) but it’s not going to be week-to-week. Could be, but I just don’t think so. But again, I’ll let the doctors decide.”

Lindholm will visit team doctors after the team arrives in Boston.

Jokiharju, meanwhile, has not played since suffering an undisclosed injury in the Black Friday loss to the New York Rangers on Nov. 28. He has been skating for several weeks now. The Finnish defenseman, who was selected to represent his country in the Olympics, has six assists and minus-5 in 25 games.

Jokieharju was set to be reunited with Nikita Zadorov, with whom he was paired last season when he was obtained at the trade deadline. Meanwhile, Jonathan Aspirot was bumped up to play on the top pair with Charlie McAvoy. While the 26-year-old Aspirot had not played an NHL game until this season, he’s been quite a find. The B’s went into Tuesday’s game in Seattle with a 16-5-1 record with Aspirot in the lineup. They are 2-0-1 since he returned to the lineup from being out with an upper body injury.

“He’s definitely back to where he finished before he got hurt. It took him a couple of games, but he’s back to being the same guy,” said Sturm of Aspirot. “As coaches, you’re not nervous but you hope he can go back to that game that made him so good. And he did. That’s why he has the trust from us to be a top guy, a shutdown guy with Charlie.”

The B’s began this trip against the Buffalo Sabres, who were at the time the hottest team in the NHL, and they’ll end it against the hot Kraken, who are 7-0-1 in their last eight games, including a 5-1 win in Calgary on Monday. … Earlier in the day, Bruins’ prospect Dans Locmelis was named to the Latvian Olympic team. The 21-year-old Locmelis, who played at UMass, has 12-9-21 totals in 30 games with the Providence Bruins.