Katherine Heigl Addresses Possible Return to 'Grey's Anatomy' (Exclusive)

The 40-year-old actress portrayed Dr. Izzie Stevens from 2005 to 2010.

Katherine Heigl isn't sure if she'd step into the role of Dr. Izzie Stevens again.

ET recently spoke with the 40-year-old actress on the set of Suits and she admitted that the decision to reprise her Grey's Anatomy character -- even in the show's eventual series finale -- would be "a tough one" to make. Heigl exited Shonda Rhimes' show in 2010 during its sixth season.

"I haven't [thought about Izzie] in years. I don't know. I don't know if I would or if I wouldn’t," she said. "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 must feel like it would just be kind of like, 'Yeah, we already let that go... why are you here?'" Heigl added.

Like with her Grey's character, Heigl also hasn't considered where she'd like her character on Suits, Samantha Wheeler, to end up at the conclusion of the show's ninth and final season.

"I haven't even thought about it," Heigl, who was a fan of the USA series before being cast last year, admitted of her character's fate. "You know, what I'm thinking more about is the other characters. What's going to happen to my favorite characters, you know? What's going to happen with Donna (Sarah Rafferty) and Harvey (Gabriel Macht)? What's going to happen with Louis (Rick Hoffman) and Sheila (Rachel Harris) and the baby? That's what I've been thinking about."

When it comes to characters other than her own, Heigl has strong opinions about where many -- specifically Donna and Harvey -- should end up.

"That would just be the worst absolute way to end this show if you have them break up and go, 'You know what, we gave it our best shot.'" Heigl said of the fan favorite couple. "Like, that would be awful. I would never forgive Suits or [creator] Aaron [Korsh]... That would be really weird."

As for how she's handling her two-season-long Suits journey coming to a close, Heigl said she's "doing OK" but is "gonna miss it a lot."

"I'm going to miss being a part of it, but I'm gonna miss being able to watch it too," she said. "Obviously being on it has changed my viewing of the show because just understanding even the space that they film in and being part of it kind of regularly now, versus watching it on television, has changed my viewership. I don't know if that's good or bad. Like, I almost ruined it for myself."

"... I'm more of a sort of bystander to all of that because I'm coming in, you know, the season before it all ends," she added. "I am wanting to hopefully just sort of stand quietly to the side and let the people who have really built this show and make it... and have made this family together have their moment to celebrate, to honor, and to be sad because I know they are."

While the end of her run on Suits is quickly approaching, Heigl said she'd definitely be open to appearing on Pearson, the upcoming spinoff starring Gina Torres as Jessica Pearson.

"That would be amazing. I love Gina Torres so much," Heigl gushed. "That was one of my sort of regrets when I came onto the show, that I wasn't going to have as many scenes with Jessica."

"I cannot wait to see that show and just see what she's doing with it. She is so badass and yeah, wouldn't that be cool?" she continued. "Just like an episode or two, nothing crazy, but, you know, maybe Samantha comes in and helps her with something... Maybe we'd just be, like, one or two more scenes where Jessica gives her some fashion advice. Like, 'This is how you should be dressing.'"

The ninth and final season of Suits premieres July 17 on USA.