There have been 69 total players that have played for the Flyers and Rangers in their careers.
Nine players currently in the NHL have played for both teams:
Jaromir Jagr, Blair Betts, Martin Biron, Steve Eminger, Ruslan Fedotenko, Mike Knuble, Ian Laperriere, Vinny Prospal and Jody Shelley.
I would count Nikolai Zherdev as well since no one will want him on their team.
Tony Amonte, Donald Brashear, Alexandre Daigle, Rob Dimaio, Nick Fotiu, Jan Hlavac, Jody Hull, Kim Johnsson, Tim Kerr, Eric Lindros, Craig MacTavish, Vladimir Malakhov, Sandy McCarthy, Petr Nedved, Ulf Samuelsson, Kevin Stevens, P.J Stock, John Vanbiesbrouck, Jay Wells, Todd White and Mike York are players who played for both teams and are possible to play in the game.
I would say that Donald Brashear, Kim Johnsson, Tim Kerr and Lindros are locked in for the Flyers, or would choose the Flyers, especially in Brashear’s case.
Vanbiesbrouck has been around the team lately and Petr Nedved seems like a good bet to play for the Rangers. Craig MacTavish is coaching, but I would think he would pick the Rangers because of his Oiler buddies and winning the Cup with the Rangers. Fotiu is a lock for the Rangers.
Tony Amonte is the really interesting guy in the group. He scored 30 for the Rangers twice but that was 20 years ago. He only played 93 games for the Flyers, but that was within the last ten years. For some reason, while I think he should be a Ranger, I think Amonte would pick the Flyers in the game.