The Bruins will have to walk a fine line if they hope to defeat the Montreal Canadiens in the coming days.

That means play hard, play with emotion, play Bruins hockey. But don’t be dumb and don’t be suckered into unnecessary penalties.

The generations of Bruins teams that played the 33 previous playoff series against the Canadiens almost always had a better chance to win when the games weren’t just about pure skill and speed — but also included elements of emotion and passion and even anger.

But the Canadiens have long been adept at knowing how to push the right B’s buttons to get players to lose their cool and seek retaliation, to lose focus on what really matters: winning.

Bruins winger Brad Marchand conceded his team has not always been as under control as it needs to be against this opponent. Take, for example, Montreal’s 2-1 shootout win March 24 at the Garden, a game in which Canadiens defenseman Alexei Emelin infuriated winger Milan Lucic with a low-bridge hip check, and B’s defenseman Johnny Boychuk lost it against the despicably villainous P.K. Subban.

“It’s an emotional game whenever we play them,” Marchand said that night. “They know that, and they poke at us a bit to try and get us to take penalties. It worked a little bit. We have to make sure we have a little more discipline than that. It’s just one of those teams that you want to hit.”

So you can bet plenty of time in advance of the belated Eastern Conference second-round series opener between these two ancient rivals will be spent talking about that fine line the B’s should approach, but not cross.

“There’s always a limit that you can push,” Boychuk said. “You’ve got to keep your emotions in check. You can be pumped up, but you have to suck it up for the team when something happens. Play hard, play with emotion, but don’t be dumb, don’t be suckered into unnecessary penalties. You have to make sure you’re playing as a team and not as an individual trying to get back at guys.”

Do the Habs deliberately try to goad the Bruins into penalties?

“Probably, yeah, I mean they’re good at it,” Boychuk said yesterday. “We seem to go for it. But it’s playoffs now. You’ve got to keep your anger and your personal vendettas at the door and you take it for the team.”

Another carryover from that March game, for Lucic, is the knowledge that Emelin can be a dangerous foe. Not merely a cheap-shot hitter like, for instance, Pittsburgh Penguins defenseman Brooks Orpik, but dangerous — a guy who may be trying deliberately to hurt people.

“Whether (the hit was) fair, legal or whatever you want to call it, if he wasn’t scared he’d stand up and hit me and not go after my knees,” Lucic said following the March 24 meeting. “It just shows how big of a chicken he is that he has to go down like that to take me down. It shows what kind of player he is. And on my end, you’ve got to keep your guard up at all times.”

That’s always the fear, beyond the Canadiens’ chippy play, their diving and whining: the threat of the extreme emotions leading to some really dangerous on-ice event, perpetrated by either side.

Recall the 2002 playoff series when Bruins blueliner Kyle McLaren lined up Canadiens winger Richard Zednik for a vicious, ugly, open-ice elbow to the head, inflicting a concussion, broken nose and fractured cheekbone.

Obviously, nobody wants to see that sort of ultra-violence, no matter how much they may despise the other side. Short of that, though, you can bet there’ll be plenty of cheap stuff going on in this series as the Habs try to get the Bruins off their game and engineer what would be a major upset.

Center David Krejci said Montreal has players who make calculated efforts to goad the B’s into penalties.

“One hundred percent (they do),” Krejci said yesterday. “They have some guys, we have some guys, who like to do that. That’s their game. Some guys are best when they’re hitting; some guys are best when, you know, they’re chatting with guys. That’s just part of the game, part of the player. We’re expecting that. I think we just have to focus on our game and we’ll be OK.

“Just play smart. It’s always going to be a little bit harder than other series, just because it’s Montreal. The emotions are high. It’s pretty easy to get out of your element (emotionally). But you’ve got to stick with it. Be smart. Have in the back of your head that you’re playing for the team, not for yourself. When something happens, you’ve got to suck it up.”

All the “be smart” talk sounded reasonable yesterday, before the puck actually drops. Once the juices start flowing and the cheap shots and trash talk start flying, staying calm is not easy for these guys.

“I think it’s just the rivalry,” winger Shawn Thornton said. “Everything is heightened because of the rivalry. The emotions are at another level. The intensity is at another level.”

Thornton and other veterans understand very well that emotion has to be part of the game plan to beat Montreal. The young guys who maybe haven’t experienced it yet, they’ll learn.

“Our guys who have been here long enough already know all about the passion in this rivalry,” Thornton said. “And the guys who just got here this year, they’re definitely going to get a good taste of it in a hurry.”