VOORHEES – Only a few grey hairs poke out of Mark Streit's jet-black locks when he's not wearing a helmet.

The Flyers defenseman is hardly a rookie. He's three years away from turning 40 and has played nine seasons in the NHL, one more than the amount of seasons Claude Giroux has appeared in.

"I'm not 30 anymore, but I still feel I can help the team and play really good hockey and I want to do that next year as well and the next year, as long as possible," said Streit, who played 397 games in his native Switzerland before 652 NHL games. "It starts with your mind. You want to do it and work good in the summer."

His 51 points are the most of a Flyers defenseman since Chris Pronger hit 55 in the 2009-10 season, yet it's not right to say that Streit is in the "prime" of his career considering he's the oldest Flyer at age 37.

"I think every player is a little bit different and it depends on what kind of game you play – if it's a physical game or you're more of a playmaker," Streit said. "I think it's mindset, too. It depends how you treat your body, how you work out, how you life your life, your lifestyle. If you want to be good, I think you can be good."

Who exactly is part of the Flyers' "core" depends on whom you ask, but Giroux, Jake Voracek, Wayne Simmonds, Sean Couturier, Brayden Schenn and goalie Steve Mason provide a place to start.

Of that group, the youngest is 22 (Couturier) and the oldest 27 (Giroux). All are significantly younger than Streit and arguably not yet in the "prime" of their careers.

What age exactly denotes a player's prime?