Inside the Pittsburgh Penguins’ locker room, those less hip to the club’s longstanding rivalry with the Philadelphia Flyers have quickly become apprised.

Franchise pillars Sidney Crosby, Evgeni Malkin and Kris Letang probably let their newer teammates know of the rivalry’s intensity and so far, through five games, the eighth all-time postseason series between the two clubs has lived up to that billing.

On Wednesday night in Philadelphia, the Penguins take the ice with their season on the line, the Flyers leading the series 3-2.

For coach Dan Muse, who’s guided the Penguins back to the playoffs after a three-year absence in his inaugural campaign in charge, team-wide emotional regulation is critical.

“We want to just focus on the things that we can control,” Muse said. “Playoff hockey is going to be physical on both sides, but we also want to make sure we’re not putting ourselves at a disadvantage and that we’re staying in emotional control. I think it’s gotten better as the series has gone on and it’s going to have to continue to be better, as well.”

Keeping emotions in check has proved to be a tall task for both clubs thus far.

For evidence, look no further than the ceaseless post-whistle scrums that develop, featuring constant shoving, headlocking, cross-checking and other extra-curriculars that the series’ officials have struggled to keep a lid on.

And by large, those after-the-play occurrences have not drawn whistles, although the Penguins and Flyers have combined for seven 10-minute misconduct penalties so far.

The two clubs have been whistled for 48 minor penalties through five games.

With every mistake having the potential to be significantly magnified, the Penguins have been aiming to tamp down the urge to engage in post-whistle confrontations.

“That’s going to be part of a series, I think we’ve got to stay out of it a little bit more and trust that when they do it and try to start it up, that they’re going to get penalized for it,” Crosby said after the Penguins’ Game 1 defeat. “But that’s more something I think they’re looking to do. We’ve got to stay out of it and trust they’ll be undisciplined.”

Through the series’ first three games, which saw the Penguins go down 3-0, Crosby’s temper flared at times, seen via some behind-the-play cross-checking with Flyers captain Sean Couturier in Game 1.

More recently, in Game 5, Anthony Mantha was on the verge of dropping his gloves on multiple occasions, while the Flyers’ Travis Konecny, Trevor Zegras, Garnet Hathaway and others have provided ample doses of antagonism.

Of late, Crosby has risen above the emotions of the matchup and put his stamp on the series, scoring a goal with four assists in Games 3-5.

Previewing the showdown, Flyers coach Rick Tocchet, a three-time Stanley Cup champion as a player (1992) and assistant (2016, 2017) with the Penguins, stressed his club’s need to neutralize Crosby.

“You’ve got to go through him. You’ve got to be on top of him. You’ve got to make it a hard game for him. You’ve got to get in his way,” Tocchet said. “Because if you’re not, you know what he can do.

“We have a ton of respect for Sid, he’s an unbelievable person and player, but we’ve got to get him in the ditches. We’ve got to make it hard on him.”

Crosby has been far from alone in receiving rough treatment from the Flyers.

Malkin also knows all too well what it’s like to be subjected to that kind of extra attention.

During the 2012 Eastern Conference quarterfinal, Couturier, then a rookie, drew pestering Malkin as a primary assignment and did so effectively. The Flyers went on to win that series in six games.

By winning two straight games to strike back in the series, the Penguins have put some pressure on Philadelphia, which has obvious incentive to finish off their foe at home Wednesday as opposed to returning to Pittsburgh for a Game 7.

From now on, mental slip-ups and lapses in restraint carry major potential consequences in a win-or-go-home scenario.

As a result, Muse continues to preach a need to remain calm and collected no matter the circumstance.

“You’ve got to make sure that your discipline is there,” Muse said at the start of the series. “The emotions run high, especially early in games and early in series. It’s important for us that we’re staying in emotional control throughout.”