CRANBERRY TOWNSHIP, Pa. — Fourteen years ago this month, the Penguins had just been eliminated from the Stanley Cup playoffs by the Philadelphia Flyers in one of the most violent, outrageous series in NHL history. While the Penguins methodically walked to the team bus in Philadelphia that Sunday afternoon, Kris Letang was deep in conversation with the Penguins’ late, great general manager, Ray Shero. The two spoke for nearly 30 minutes.

Years later, Shero explained what that conversation entailed. Simply put, Shero knew that the Penguins’ foundation of stars was going to play for championships well into the future. To win again in the playoffs — this was during the period when the Penguins had earned one Stanley Cup championship, but were suddenly dealing with the reality that the playoffs weren’t always fun and games — they were going to have to learn to keep their cool. Even then, Shero had identified that the Big Three’s weakness was its habit of letting agitators get to them. That Letang, Sidney Crosby and Evgeni Malkin almost cared too much. Four years later, Mike Sullivan was part of a new regime, but spotted the same problem, which led to his “just play” mantra.

The words “just play” are inscribed on the inside of the Penguins’ 2016 Stanley Cup rings. By that time, the Big Three had learned to channel all of that emotion, and it helped them become champions again. And again the next season.

Checking out that jewelry might be a good idea before Game 2 begins.

By the time Game 1 of the Penguins-Flyers series had concluded, each of the Big Three had lost their cool. Not only did they all struggle in certain ways, but they were engaged in far more extracurricular activities than were advisable.

“We know it’s Philly, we know it’s the playoffs, we know it’s coming,” Malkin said. “I like to play physical, I like to play a hard game. But just after a whistle, we need to just, like, go away and play smart. It’s the only way because they (referees) allow it (stick work). This game, cross-check, you know? But again, we know it’s coming. But everybody should be a little bit smarter. That’s it.”

Easier said than done, of course.

In the first period, Malkin got away with a penalty behind the play and found himself in numerous post-whistle scrums. Later in the game, he was on the ice and engaged with the Philadelphia bench while the five skaters for each team were lined up for a face-off. He was also going out of his way to initiate hits and, while he’s hardly one to shy away from on-ice violence, he hasn’t sought contact at any point this season the way he did on Saturday night.

He wasn’t alone.

Crosby found himself in the penalty box twice, both penalties that displayed an uncharacteristic lack of discipline. In the first period, he was penalized for removing Jamie Drysdale’s helmet while entering the Flyers’ zone.

Late in the third period, with the Penguins down 3-1, Crosby engaged in a battle with Travis Sanheim. While Sanheim certainly committed his share of infractions before referee Chris Rooney finally raised his arm, Crosby basically dared the officials to call a penalty with a pretty nasty slash.

Letang joined the party on occasion as well. He also found himself in the penalty box and was consistently yapping with members of the Flyers, who were all too pleased to provoke such a reaction.

“It’s what we talked about,” Malkin said. “We should play our game. I think we, a little bit, lost control in the second period. … We started fighting. This is what they want, you know?”

Letang wasn’t interested in speaking about the Big Three losing its cool. He was specifically asked about that very topic and deflected the query far more than he resisted the urge to join in battles against the Flyers.

“We just have to focus on what we do well,” Letang responded to a question about the Flyers goading the Penguins into post-whistle confrontations.

What they do well historically isn’t post-whistle battles.

Quite to the contrary.

Erik Karlsson, a veteran himself who has played in multiple playoff series against the Big Three, suggested that the Penguins played too hard on Saturday.

He wasn’t specifically talking about Crosby, Malkin or Letang, but he might as well have been. Karlsson said the Penguins played with too much emotion, and that much is clear, but they also typically follow the play of their leaders.

“They just played a better game than us,” Letang said. “They played with a bit more urgency than us.”

They also won the psychological game, just as they did so frequently during the 2012 playoffs.

“It’s just the first game, but we need to regroup and come back for the next game Monday,” Malkin said.

It’s understandable why emotions are running high for the Penguins’ biggest names.

Crosby, 38, is in the playoffs for the first time in four years, and this comes only two months after an injury knocked him out of what may have been his final Olympic tournament. Waiting for Crosby in the first round of the playoffs was the team that he dislikes the most.

Malkin, 39, is in the final year of his contract and doesn’t know if he will play for the Penguins beyond this season. After every game, he’s joined by his son, Nikita, in the locker room. His son is old enough (9) to appreciate what his dad has done, what he means to Pittsburgh, and what this postseason means to him. It’s a lot.

And then there is Letang, who turns 39 on Friday. Of the Big Three, his play has clearly deteriorated the most during the past couple of seasons. He has two years remaining on his contract, but it’s safe to wonder if he’ll play two more seasons in Pittsburgh, regardless of the contractual situation. This postseason means everything to him, too.

There is much on the line in these games. Maybe almost too much.

“It’s just one game,” Letang said. “You have to focus on the aspects you didn’t do well.”

Keeping their cool would be chief among them.

NOTES — The Penguins did not sustain any injuries in Game 1 … While the Flyers held an optional practice at PPG Paints Arena on Sunday, the Penguins went with a mandatory workout at the UPMC Lemieux Sports Complex. Dan Muse opted to keep the Game 1 line combinations and defensive pairings intact for practice, typically — but not always — a sign that he will use those same configurations in Game 2 … Rookie Ben Kindel turned 19 on Sunday. He became the youngest member of the Penguins to appear in a Stanley Cup playoff game since Jordan Staal in 2007.