PHILADELPHIA – It's old hat for Shayne Gostisbehere to play at Wells Fargo Center. The 21-year-old defenseman won an NCAA championship in the same barn with Union College back in April.

He was a Flyers prospect then, but decided to forego his senior season to sign a pro contract so now it's a whole different game.

"It's pro hockey," Gostisbehere said. "It's an honor to put on the sweater for the first time and I'm just gonna go out there and have some fun."

The 2012 third-round pick donned a Flyers uniform against the Washington Capitals last week, but that was a rookie game. Monday he'll make his preseason debut against Washington with Craig Berube behind the bench, not Lehigh Valley Phantoms coach Terry Murray.

" You just go out there and play your game," Gostisbehere said. "The vets are with us now. We're intertwined with them. It's gonna be fun out there. We're just gonna go out there and play our game."

Although Gostisbehere will be playing on a team with eight veterans, his defense partner will be a fellow rookie in Robert Hagg, the Flyers' 2013 second-round pick.

Hagg, a lock to be with the AHL Phantoms this season, admits he's still adjusting to the speed of the North American game. Aside from the rare tournament in the U.S. or Canada, his primer to North American hockey was a 10-game tryout with the Phantoms after his season in Sweden ended last season.