A tradition in Matt Cullen’s household was born six weeks ago during the Pittsburgh Penguins’ opening-round playoff series against the New York Rangers.

Every night before bedtime Bridget Cullen, Matt’s wife of 12 years, grabs the Penguins’ team-issued scouting report — a booklet breaking down the opponent’s system and tendencies.

With her husband and three sons — Brooks, 9, Wyatt, 7, and Joey, 6 — in their “undies” in the master bedroom, they begin a half-hour stretching routine as Bridget reads verbatim as if she’s helping them cram for a test.

“It’s the cutest thing ever,” Bridget Cullen said, laughing. “We go over the whole report together, and the kids are explaining to Matt what he needs to do to score and giving him all sorts of funny things that go through their mind.

“We beat the Rangers, so we kept it going.”

Three rounds later, Cullen finds himself three victories from his second Stanley Cup 10 seasons after winning his first with the Carolina Hurricanes.

Cullen — the Virginia, Minn.-born, Moorhead, Minn.-raised, St. Cloud State-produced 18-year NHL veteran — is knocking on 40’s door. He thought last season might have been the end of the road after playing out his contract with the Nashville Predators.

Penguins General Manager Jim Rutherford, who twice acquired Cullen when he managed the Hurricanes, called with a job offer last July. Rutherford was honest. Cullen would have to accept being a fourth-line center who could move up the lineup in case of injuries.

Cullen did just that during Monday’s Game 1 victory. During the third period, he skated with Evgeni Malkin after Bryan Rust was injured.

“Jim has so much faith and trust in Matt,” Bridget said. “It’s just nice to have that in your corner.”

Ten years ago, Bridget was pregnant with the couple’s first child. So, to get to experience all this again with his hockey-mad sons, Matt calls it a “blessing.”

Well, except for the fact that their kids critique him like their hockey-mad mom, who once was so perplexed by her husband’s turnover in Dallas while he played for the Wild that she had the video cued up on the DVR when he arrived home from the road trip because she wanted to know what he possibly could be thinking.

“Against Washington [in Game 4], Matt scored a big goal but had a chance to come down and score again later,” Bridget said. “He hits the crossbar. The boys, which they get from me, were all over him after: ‘Dad, what the heck was that? You have to put those in. You could have had two goals in the biggest game ever.’

“Matt was like, ‘I don’t even get a high-five for the goal I scored?’ I was like, ‘Oops, I’ll take credit for that.’ ”

Humbling start

At NHL drafts, first-round picks are ushered onto the stage for pictures with team brass. Subsequent picks, a team representative finds and escorts the player to the draft table.

Cullen was selected 35th overall in 1996 by the Mighty Ducks of Anaheim.

“Matt hears his name, stands up, hugs his parents, looks around and kind of sits down because nobody from Anaheim made their way over,” longtime pal and former teammate Mark Parrish said. “A couple minutes later, a guy comes running over and is like, ‘Sorry, we couldn’t find you.’

“That’s how it all began for Cully.”

Nobody in the 1996 draft has played more regular-season games than Cullen’s 1,294; add 93 playoff games to that. Five players from that draft still are playing in the NHL.

Parrish, who still remembers Cullen as a peewee and bantam, can’t believe he’s still playing.

“I didn’t know his name, but I just remember there was this No. 9 on Moorhead that I hated because he always had the puck and we could never get it away from him. That little lefty,” Parrish said. “We developed this little personal rivalry.”

Parrish eventually learned Cullen’s name. They became friends on the Southside Stars.

“We maybe fudged a little bit where some of the guys came from. Moorhead isn’t very south,” Parrish said, laughing. “We’d go up to Winnipeg, and we’d swing by on the way and steal Cullen and [Thief River Falls’] Wyatt Smith.”

A long career

Parrish scored his first high school goal at Moorhead and his Bloomington Jefferson Jaguars beat Cullen’s Spuds in the 1994 state championship game.

“The name Jeff Heil still keeps Matt up at night,” Parrish said. “Cully probably had 10 point-blank chances and [goalie] Heil robbed him blind all game long. Cully had us beat by himself.”

Parrish and Cullen became linemates for two years at St. Cloud State. Parrish was taken 79th by Colorado in that same 1996 draft; he played 722 NHL games, retiring in 2012.

Yet, Cullen keeps going.

“He was the worst skater out of all of us,” Parrish said. “Even I beat him by a nose. As he gets older, his skating gets better. That’s not the way this world’s supposed to work. It’s a testament to his work ethic.”

Cullen’s fitness is why Rutherford was willing to sign a player who would turn 39 last Nov. 2.

“I know how he takes care of himself. That’s why he’s still playing at this point of his career,” Rutherford said.

His workout regimen is off the charts.

“Nobody sees what he does in the offseason,” Bridget Cullen said. “It’s not like he’s going home and drinking beer at the lake.”

Enjoying the ride

Cullen has four goals this postseason, is a mainstay on the penalty kill and a role model in the locker room. His 16 goals in the regular season were his most in six years. And he’s cherishing this playoff run. After the Eastern Conference championship, he was tickled while watching his three boys dance around the locker room high-fiving his teammates.

“I absolutely love it,” Cullen said. “I grew up a rink rat. I grew up in locker rooms my whole life. To be able to share that with my own boys at an age where they’ll remember it, it makes this mean so much more.

“I can’t teach my kids to pound a nail, but to be able to bring them in the rink and give them this experience, it’s something I’m most proud of.”

Not shockingly, Bridget says her husband is the calmest one in the house.

“She’s got the three boys wound up so tight, it’s hilarious,” Matt said.

Last year, Cullen talked publicly about the possibility of retiring. His agent, Pat Morris, told him never to do that again.

So he won’t think yet about next season. There will be plenty of time for that.

“Because you spend a little time playing in this league, you realize exactly how hard it is to get here — it takes an awful lot,” Cullen said. “It really does. And you know what? It’s as much fun as I remember it in 2006. There’s nothing better.”

Years ago, Cullen’s Fargo home was burglarized. His wife’s Stanley Cup ring was stolen. The Hurricanes presented her with another, but gone is that original. She could be close to another.

“I’m not looking that far ahead. I won’t,” Bridget said. “I can’t even think about it. And we won’t talk about next year either. Everyone talks about the future all the time. We’re like, ‘Wait, let’s just be in this and enjoy it and completely embrace this.’

“I’m just so proud of Matt. Plus, he’s a good guy. He’s really deserves this. This is pretty much like a dream.”