Tina Majorino Tina Majorino

As one door closes, another opens.

Tina Majorino has landed a guest-starring role on the upcoming season of Grey's Anatomy, TVGuide.com has learned exclusively.

Grey's Anatomy: Will Arizona Robbins and Mark Sloan die?

Details on Majorino's role are being kept under wraps, but executive producer Shonda Rhimes recently told TVGuide.com that just because they've hired some new actors — like the previously cast Gaius Charles and Camilla Luddington, who also guest-starred alongside Majorino on True Blood this season — does not mean they're filling the supposed vacancies left by the death of Lexie (Chyler Leigh) and the exit of Eric Dane from the series.

"It's really interesting that everybody seems to think we've hired new series regulars," Rhimes said. "It's not. We hired some really lovely guest stars who are doing some really lovely guest-star stuff. It boils down to the fact that all our doctors are attendings and one of the things that I want to see our attendings doing is teach, so that's what we're seeing."

Grey's Anatomy's Shonda Rhimes talks Season 9: Time jumps, new locations and new docs!

Majorino, 27, most recently guest-starred on True Blood, in which she was killed off during Sunday's episode. Her other credits include Napoleon Dynamite, Veronica Mars, Big Love, Bones and the short-lived ABC drama The Deep End.

Who do you think Majorino is playing? Could it be a new doc at Seattle Grace? Or even at the other hospital Rhimes hinted would be featured this season? Maybe she's a patient, or even someone who rescues the docs from the woods. (Hey, it could happen!) Hit the comments with your thoughts.

Grey's Anatomy returns Thursday, Sept. 27 at 9/8c on ABC.