Is Grey’s Anatomy is about to weather another major cast shakeup?

On Wednesday afternoon, Sara Ramirez — who has played Callie Torres for more than a decade — posted a message on Twitter that has fans wondering if she’ll be returning for the ABC drama’s recently-ordered 13th season.

It’s entirely possible Ramirez was simply celebrating her final day of work on Season 12 (Grey’s is currently in production on its May 19 season finale). It’s also possible the actress — whose contract is set to expire in June — was looking to increase her negotiations leverage. And then there’s the possibility that she has, in fact, decided to call it quits.

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In a possibly telling sign, Ramirez’s personal reps have not responded to TVLine’s multiple requests for comment. An ABC rep, meanwhile, did get back to us, but declined to comment on the matter.

If Ramirez does opt to hang up her scrubs, this would mark the third major Grey’s exit in as many seasons, following the departures of Sandra Oh (in Season 10) and Patrick Dempsey (in Season 11).

Ramirez, who joined Grey’s in its second season, is one of several longtime cast members whose contracts are set to expire at season’s end. Her longtime scene partner Jessica Capshaw, however, is not one of them. As TVLine exclusively reported, Capshaw inked a new three-year deal with the show last May.

On-screen, Ramirez’s Callie is gearing up for a heated custody battle with Capshaw’s Arizona, one triggered by Callie’s desire to follow current squeeze Penny to New York with her and ‘Zona’s daughter.

Thoughts? Are you bummed to see another Grey’s vet check out? Care to predict how Callie will be written out? Hit the comments!