Probably not possible, BUT maybe with the NBC Sports app. In some regions they allow local sports too, where they have CSNs. Won't get you the Eagles, might get you some Phillies. Might be blacked out IF you are actually in Philly. You might also have to sign in with a cable or FIOS subscription so if you have "cut the cord" it won't work.
What Apple TV do you have? Gen 3 or 4? Or Gen 2 or 1? If Gen 2 or 1 are you jailbroken? If you are jailbroken PM me.