Antonia Thomas departing The Good Doctor after 4 seasons

The Good Doctor will be saying goodbye to Antonia Thomas, who portrayed Dr. Claire Brown on the medical drama for four seasons, during tonight's season 4 finale airing on ABC at 10 p.m. Reps for Thomas confirmed the news to EW on Monday.

"It was a really, really difficult decision, and leaving, I have to say, is a bittersweet thing for me because the last four years have been absolutely incredible," Thomas told Deadline who broke the news.

"I feel so lucky and basically indebted to David Shore and the writers for having the experience to play Claire, who has just been a wonderful, wonderful character to explore, so layered and complicated and flawed, the kind of character that I think an actress dreams to be able to play," she continued. "I think, ultimately, for me, it's about coming to the point where I think we've really run the gamut of different things that Claire can have gone through, and I'm now really excited to explore different creative opportunities."

The British actress was a star across the pond before joining The Good Doctor, thanks to her breakout role in sci-fi dramedy Misfits. Leading roles in multiple small screen projects followed, including Love Sick, the mini-series Homefront, and voiceover work in the BBC's Teletubbies.

"For me, as an actress, having versatility and creativity has been something that's been really, really important," Thomas said. "I've come from the British system where you play a role, you film it for a couple of months because seasons are only six episodes long, and then you can do something else, and I think after dedicating four years to Claire and her journey and really, really exploring the character, I am just now ready to try something new, ultimately."

Thomas said she first voiced plans to move on after season 3, which led to a discussion with David Shore, who developed the series based on the 2013 South Korean series of the same name. She said once plans were announced for her to exit after the season 4 finale, her costar and dear friend Freddie Highmore — along with the rest of the cast — were all supportive of her decision.

The good news for The Good Doctor fans is that Thomas is hoping she'll be able to return to the series as a guest star in the future. So you may not have seen the last of Dr. Claire Brown just yet.

"I've had conversations with Freddie about coming back, and absolutely, yes. Really for me, if there was more time in the year to be able to shoot the show and to be able to go off and do some of the other things that I'm wanting to explore now, I'd do both. It has not been an easy decision for me to leave, so I absolutely would love to come back every now and then and say hi, I'm very much looking forward to that," she said.

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