Flyers fans don’t care if they’re underdogs. The ‘vibe is immaculate’ as the Keystone Rivalry is renewed.

If there’s one thing Philly sports fans love, it’s an underdog story.

Jeni Green, from Allentown, and Kristin Iwancio, from Harrisburg, who were both on hand for the Flyers’ regular-season finale Tuesday, said it’s just the Philly sports mentality to hope for the best — but expect the worst.

However, sometimes you end up pleasantly surprised, like with the Flyers’ playoff berth.

“We all know how the last underdog story in Philadelphia went, so we’re hoping for another one this year,” Iwancio said.

» READ MORE: After 13 years and 820 games, Rasmus Ristolainen says it ‘feels good’ to finally make the playoffs

For William Bailey, a Delco native and Flyers fan since 1971, he’s not expecting the team to be a real Stanley Cup contender, but he has found “an unexpected pleasure” in what the team has accomplished this year.

“I’m excited if they do [have] a good run, as far as it goes,” Bailey said. “I know they’re early in the rebuilding process.”

Some, like Bailey and his wife Holly from Brookhaven, have experienced multiple playoff runs and even two Stanley Cups as Flyers fans. For others, like 10-year-old Roman Radcliff of Lancaster, it’s a whole new experience.

Radcliff, who was dressed in an orange morph suit with a Flyers jersey on top, was 4-years-old the last time the Flyers made the postseason and 2-years-old the last time they played a home playoff game. He has no recollection of the experience.

» READ MORE: This Flyers fan got a giant ‘Halloween Gritty’ tattooed on his head. He hopes it brings the team good luck.

Getting to witness his team play playoff hockey, especially because he wasn’t expecting it this year, is the most exciting part for him. The Flyers’ opponent in the first round only adds to it.

“Keystone Rivalry — I can’t wait to see them do that,” Radcliff said.

The Flyers will take on their cross-state rivals, the Penguins, in the first round of the Stanley Cup playoffs, with Game 1 set for 8 p.m. Saturday in Pittsburgh.

It’s a rivalry that runs deep, especially since the Flyers’ last home playoff game in 2018 was against the Penguins. The Flyers lost that series, 4-2, and gave up eight goals in Game 6 in Philly.

Flyers fans have not forgotten — nor forgiven.

A cleaners in Collingswood called Penguins Cleaners has changed its name to Flyers Cleaners for the first round, even dressing their mascot in a Flyers jersey. Hopefully it doesn’t have the same effect as dressing the Rocky statue in an opposing team’s jerseys.

The Penguins are the betting favorites, but for fans like Green, that’s not such a bad thing.

“I don’t think it’s going to be easy. I mean, I think Pittsburgh is fantastic, and we all know that. I think on paper, they are the favorite,” Green said. “But I think Philly teams thrive on that, and I think this team is really capable of thriving under that pressure.”

» READ MORE: Some wanted to change Trevor Zegras. The Flyers let ‘Z be Z.’ Now, he’s got his ‘swagger back.’

Pittsburgh has the advantage of a strong veteran core with postseason experience, which Green thinks contributes to the underdog narrative the Flyers have been assigned.

“I think the young guys really have the heart, and I think they have talent that gets counted out based on the experience,” Green said.

Bailey identified a more physical advantage to having a team this fresh.

“We’re going to have more energy. That’s the way I look at it,” Bailey said.

His wife sees the way the energy has impacted the team all season, especially toward the end of their playoff push.

Holly Bailey said if the team brings the same passion against the Penguins they brought against the Winnipeg Jets in their 7-1 win last week, it should be a much more competitive series than people are anticipating.

“It’s nice to see them have that kind of level of energy and not take the foot off the pedal,” she said. “So they go into the series with that kind of energy.”

» READ MORE: Five things to know if you are just jumping aboard the Flyers’ playoff bandwagon

Kevin Kasbar of Greenwich, N.J. knows a thing or two about supporting younger players. Kasbar’s interest in hockey was heavily influenced by the Simon Gagné era of the Flyers, which started when Gagné was 19-years-old.

He has watched every playoff run the Flyers have made since. But Kasbar said there’s “something about this one” because of the young core at the center of it.

“They’re glue. They’re sticking together. It’s very impressive,” Kasbar said.

But if Kasbar had to pick a key factor in the Flyers success, it would be goaltender Dan Vladař.

“Vlady coming in, being a stellar goalie, I don’t know how he’s not in conversation for the Vezina [Trophy],” Kasbar said.

Whether it’s an early exit or a deep-run no one anticipated, playoff hockey has returned to Philly, and fans are “Flyer’d up” to experience it again.

“I dressed like a pumpkin today,” Holly Bailey said in her orange Flyers shirt and matching orange pants.

“That tells you something — and I stand next to her, so that tells you something else,” added William Bailey.

» READ MORE: Did Pope Leo bless the Flyers and put them on the path to the playoffs? We investigate.

Iwancio believes there is something to be said about any playoff environment in Philly. But there is something extra special when fans have waited so long, and through a rebuild, for it to return.

“I’m surprised we weren’t watching people climb poles [Monday] night, and that’s just getting into the playoffs,” said. “For anyone who’s been in Philly, when that’s happening, the vibe is immaculate. You can’t match it anywhere else.”