The actress also revealed where Shonda Rhimes stands on a potential 'Private Practice' reboot.
Kate Walsh is picturing what Grey's Anatomy will look like without Meredith Grey. ET's Nischelle Turner spoke to the 55-year-old actress about how the ABC series will continue after Ellen Pompeo's exit, which will likely happen after her limited season 19 role.
"I imagine she'll pop back in," Walsh said of Pompeo. "I don't know what they've got in mind."
While Walsh, who plays Dr. Addison Montgomery on the series, isn't sure what the future holds for Grey's, she knows the future is bright for the series.
"I love what they've done this season. I love their whole take with the new interns... They've all got issues, they were not first on the list for med school, they've all got problems," Walsh said. "I think that's a really interesting angle. It's such a great group of actors. I think that construct itself, of the teaching hospital, the idea of the experts, the attendings are still fallible... that aspect is what the winning formula was, to watch people that are sort of mentoring others. There's something really powerful about that and I think that structure still works in the show."
"Plus, the writing is better than ever... It's really tight and really smart," she continued. "I think one of the other things that [creator] Shonda [Rhimes] had established when she created the series was the ability to write great, entertaining, high stakes, soap opera kind of madness, but [in a] super intelligent [way, while] also addressing social issues, and bringing people in, and getting them to look at aspects of culture and life from all different perspectives, and hopefully growing their compassion and empathy and opening their minds up. That can go on and on and on as far as I'm concerned."
Grey's mid-season finale seemed to set up Pompeo's impending departure, as Meredith accepted a job in Boston. With the new chief heading out the door, Grey Sloan will need a new person to lead it... could that be Addison?
"I don't know how that would work 'cause I'm based here in Australia. I'd have a lot of work," Walsh told ET. "I mean, never say never to anything."
As for what is up next for Addison, Walsh teased, "It's gonna get really rich and it already is."
"It's really incredible what they're writing. It's just very, very powerful," she said. "... They're showing it from all different angles and it's very real and very powerful and very of the moment. I think people are gonna wanna stay tuned to see what happens, because it gets pretty hectic."
Whatever her future on Grey's holds, Walsh said she'll "never forget" her first appearance on the series, in which she put a damper on Meredith and Derek's (Patrick Dempsey) romance by showing up and announcing she's McDreamy's wife.
"That entrance that Addison made... I probably got more attention for that minute of a scene than anything I'd ever done before," Walsh said. "That was the day my life changed in a massive way... To be a part of a show... [that became] a cultural phenomenon... it was a pretty powerful experience to have with all those actors. All of our lives changed in a massive, massive way."
Walsh herself landed a Grey's spin-off with Private Practice, which ran for six seasons from 2007 to 2013.
"Shonda also said a month ago that she would love to revisit Private Practice. I was like, 'Really? Oh cool!' So anything's possible in this crazy world," Walsh revealed of the show's creator, before admitting that she has "no idea" if a reboot may come to fruition.
"That's all in her creative [control]," Walsh said of Rhimes. "... She could do anything."
Even when Private Practice wrapped, Walsh stayed in the Grey's world by frequently returning to the beloved medical drama.
"It's great. It's like a little salmon slipping into the stream. I'm like, 'Oop, I'm back,'" she joked. "It's really easy and it feels great. It's like going home and all the good things. The writing is so strong and I love getting to work with my old friends... There's just light. I just love it."
"It's so good. It's just bigger, more fabulous, funnier, stronger, faster, more gorgeous. Paris really opened up their arms to this show and... just kind of rolled out a red carpet for us wherever we went to shoot. It is stunning," Walsh said. "The costumes are more fabulous than ever. The storylines are getting really intricate... We've got this gorgeous escapist, fabulous world that is just so delightful to participate in. It's joy, it's just pure joy... It's been a real joy and pleasure to play."