The Bruins earned their most emotional victory of the season in a third-period comeback against an average St. Louis Blues team.

But they’ll struggle to keep the good vibes going much longer than the average sugar high. Next on the menu are the Dallas Stars, a team that outclassed the Bs at the Garden on October 24. And they will face the Stars without the defenseman who had been their best defender — at least offensively — until Tuesday. Hampus Lindholm left the game in St. Louis after blocking a shot that appeared to hit him on the inside of his right knee. There’s no real timetable for a return for Lindholm, whose offensive play has earned him top minutes on the power play.

After practice in Dallas on Wednesday, coach Jim Montgomery announced that Lindholm would be out for “weeks,” which isn’t exactly what the B’s need at the moment.

“So “weeks” is plural. Don’t ask me next week,” Montgomery said.

The news wasn’t exactly unexpected since Lindholm was unable to return to the bench after being injured on St. Louis’ first-period power play, but it wasn’t good news nonetheless. The offseason plan was to create the identity of a team capable of closing out close, low-scoring games. But so far, this plan is still at the ambition stage. Lindholm is the second top-six defenseman to suffer an injury. Andrew Peeke is still out “week to week” due to an upper body injury he suffered in Toronto last week. The B’s are currently ranked 20th in goals against (3.18 per game).

To fill Lindholm’s spot in the lineup, the B’s brought in 32-year-old defenseman Jordan Oesterle from Providence. Oesterle has 371 games of NHL experience in Edmonton, Chicago, Arizona, Detroit and Calgary and played well in Providence, posting 3-5-8 totals in nine games there.

“He is an excellent skater in all possible areas, his edges, his pivots, his lateral movements at the offensive blue line, his recoveries. And then it’s his brain. He’s a really smart hockey player who is exceptional at releasing and transitioning pucks,” Montgomery said of Oesterle.

One thing the B’s will want to do against the Stars is stay out of the box, something they haven’t been able to do all season. They awarded a league-high 84 minor penalties, and what’s worse, the shorthanded penalties are nowhere near what they’ve been in recent years. They are currently ranked 26th in PK with 73.6%. Even the Blues and their power play then ranked 32nd (the B power play took last place) scratched them for two PP goals on Tuesday.

When the B’s played the Stars late last month, they gave up three straight power play goals in the second period that pretty much ended the game.

So Montgomery, who has seen his club take a step forward but fall back in its next match all season, knows that victory against the Blues hardly guarantees an upward trajectory.

“It hasn’t happened yet. We haven’t built that consistency,” Montgomery said. “There were a lot of positives from (Tuesday) night and we’re trying to build on those. Well, see (Thursday) evening. It’s a new day.