For several seasons, the Flyers core group of leaders was comprised of the same trio of players. Claude Giroux, Jake Voracek and Wayne Simmonds have been at the forefront season after season and still are.

But as the Flyers start to put more of an emphasis on the future, the core is already changing.

Often times, the Flyers blueprint to building a contender has the focus shifted to the familiar core players and just how much time is left in their prime years. Indeed, time is dwindling for players like Giroux, Voracek and Simmonds to be true leaders in every sense, not just in leadership but in contributions on the scoresheet as well, despite career years by both Giroux and Voracek this past season.

That said, the Flyers core is continuing to evolve and transition, and as the future starts to become the present, the core is no longer just the three top players any longer.

The Flyers have spent the past couple of seasons starting to inject youth into the lineup. In just the past couple of seasons, these young players have already established themselves as part of the evolving core.

Sean Couturier was already a veteran player, but not really fixture in terms of point production. While his presence defensively was always vital, his lack of offense always left more to be desired. Early in his career, as long as the Flyers had a Danny Briere or Brayden Schenn or somebody else taking a more central role offensively, Couturier was more of a role player than a core player.

Last season, that changed. The departure of Schenn aided in it, but Couturier also took the lead playing with Giroux.

For the numerous prospects drafted in recent years, it started with Shayne Gostisbehere. In a Calder-worthy season, Gostisbehere became a fixture of the Flyers offense and instantly became a focal player in the lineup.

The following season, Ivan Provorov and Travis Konecny joined the lineup. There were a few growing pains for both, but by their second NHL season in 2017-18, they were clearly established players in the lineup and part of the Flyers new core.

It's also fair to include Nolan Patrick in this group as well. By the numbers, Patrick wasn't among the team leaders in points just yet, but his strong second half as well as the potential he carries as a second-overall pick.

So Gostisbehere, Provorov, Konecny and Patrick join Giroux, Voracek, Simmonds and Couturier as part of the Flyers core, which only continues to evolve as the team continues to watch players develop and reach the NHL.

The noticeable absence here is a goaltender and the Flyers certainly hope that Carter Hart is that piece coming soon. Defensively, typically a top pairing qualifies as part of the core of the team, a pairing that really can't be broken or a pair of players that are vital to the team's success.

Provorov and Gostisbehere were paired for part of the season, but they certainly don't have to remain a pairing on the ice to still be an important part of the team's core.

Provorov has already developed into a top-pair defenseman. Gostisbehere saw his defense take a big step in the right direction last season to accompany his offensive skills.

Among forwards, having a quality top six can help define a team and its core. The Flyers had an established top line with Giroux, Couturier and Konecny late in the season. Patrick, Voracek and Simmonds certainly remain an important part of the team as well. The Flyers are then also hoping that they can add to that group as well with Oskar Lindblom reaching the NHL and Morgan Frost making noise in juniors this season.

It is all part of the Flyers process to building a contender. A few seasons ago, there was a lot made of the Flyers wasting the prime years of Giroux, Voracek and Simmonds, mainly because those three players were all the Flyers had in their core at the time while trying to patch the other parts of the lineup in waiting for the prospects to arrive. With a few of the prospect now here and starting to establish their place in the NHL, the Flyers core is starting to make the transition to the future, growing and evolving more and more every year.

Kevin Durso is Flyers editor for SportsTalkPhilly.com. Follow him on Twitter @Kevin_Durso.