The actress left the show under a cloud after falling out with creator Shonda Rhimes, but there has been new interest in her returning as Dr. Izzie Stevens if the medical drama should ever end.
"I don't know if I would (go back) or if I wouldn't," she tells Entertainment Tonight. "I almost feel like that would almost be distracting again to, sort of, what they've done with that show in the seven years since I left... and what that's become and what it is to the fans now.
"It feels like it would just be kind of like, 'Yeah, we already let that go... Why are you here?' "
Heigl is back on TV as one of the stars of the ninth and final season of legal drama "Suits". She plays Samantha Wheeler on the show, which returns for its last run in the U.S. on July 27.