BOSTON – After seeing how events unfolded in the third period of Wednesday night’s game in Montreal, Bruins Coach Claude Julien admitted he has some thinking to do.

Specifically, Julien has a decision to make before Saturday night’s Garden visit by the Tampa Bay Lightning on whether to keep his first two lines as they were in the final 20 minutes in Montreal, or revert to the season-long setup.

The Bruins had gotten little done offensively in the first two periods against the Habs, trailing 1-0, so Julien swapped his top right wingers.

Tyler Seguin moved up with David Krejci and Milan Lucic; Nathan Horton dropped back with Patrice Bergeron and Gregory Campbell.

The result was a 2-1 Bruins’ win, as Seguin scored one goal and set up Krejci for the other. The re-shaped No. 2 line also had its best period of the game.

So, does Julien stick with what worked so well at the Bell Centre, or go back to the Lucic-Krejci-Horton trio that’s been the team’s best this season?

“That’s a good question,” said Julien after 10 Bruins had a brief skate.

“It’s something I have to think about a little longer for sure. Do I try it a little longer or do I go back to our regular lines? It’s good I’ve had a couple of days to think it over. Hopefully the decision will be the right one.”

The importance of the game against the Bruins’ archrival — and, indeed, the importance of every point in the standings during the lockout-shortened season — led Julien to make the shake-up during the second intermission Wednesday.

“I said at the beginning of the year we’ve got a short season here, so we’re going to have to make those kind of decisions a little quicker,” said Julien.

“With an 82-game schedule, you can afford to be a little more patient. (Wednesday) night it was a situation where I had to react, because I didn’t feel we had a lot of scoring chances. We were down by a goal and we had to get some scoring chances. It was one of those nights where it worked out.”

But what to do now against a Lightning club also off to a strong start, leading the Southeast Division with a 6-4-0 mark.

“We don’t want to overlook the fact that that line with (Horton and Lucic and Krejci) was our best line (in most games),” said Julien.

“It’s not that they were bad (for two periods in Montreal); it’s just that they weren’t generating much and neither were the other lines. So we made a switch.

“It was just a bit of a spark. Sometimes that’s what you need. It’s nice to know you can move guys around and there are still good things happening. I just felt that by moving those two, we might get something going on both lines. And they both had some great opportunities.”

The switch worked immediately, as Seguin scored on his first shift with Krejci and Lucic — a threesome that played together a lot last season after Horton was lost for the year with a concussion in late January.

The Bruins hope that Seguin is now back on track. He had just 1-3-4 totals in the first eight games, as he adjusted from the free-wheeling play of the Swiss league in the fall to the tighter ice and more responsible two-way hockey required in NHL rinks.

“Obviously it’s a big weight off his shoulders to get a goal like that, a big goal as well,” said Lucic. “Hopefully he can build from that. He’s got a great shot and great scoring ability; confidence is a big part of it.”

The players involved had no idea what their coach was thinking.

“Not a question for me; I have no idea,” said Seguin. “I’m just ready to play with whoever. Whether he puts me with that line or I stay on (Bergeron’s) line, I’m not thinking about it too much.”

Said Lucic: “Obviously it’s the coach’s decision. I think he wanted to create a spark going in that third period, and it worked right away. Last year we had a lot of success together when Nate went down and Tyler stepped in. We were able to create some chemistry. It was there again. We’ll see what happens going into (Saturday).

“Regardless of whether it’s Nathan or Tyler, they’re both really, really good hockey players. I feel fortunate that I get an opportunity to play with either one of them.

“With us having depth in our lineup, we have flexibility to move guys up and down and try different combinations. It seems to work out well.”

When his line-juggling worked so well against the Canadiens, how did Julien feel?

“I felt,” he said, “like I was doing my job.”

And, in fact, did it quite effectively.