Catherine Fox's Prognosis Doesn't Look Good on 'Grey's Anatomy' — Is Debbie Allen Leaving?

The Devil works hard, Kris Jenner works harder, and Grey's Anatomy works the hardest. Grey's has been a fixture on television for 20 years and counting. And while Ellen Pompeo stepping back from the series could've negatively affected the show, somehow, the Shonda Rhimes medical drama continues to keep fans intrigued. A new batch of residents makes new yet familiar mistakes, and the more seasoned doctors still find themselves in tons of turmoil.

Debbie Allen, who joined the series later, has become a mainstay as Dr. Catherine Fox (nee Avery) and the show's executive producer. Season 21 focuses on Catherine's health, raising questions about Debbie's future on the show. Is the storyline a sign that Debbie is leaving Grey's Anatomy for good? Here's what to know.

Debbie debuted as Catherine in 2011. Since then, she's kept fans intrigued by portraying Catherine and Dr. Richard Webber's (James Pickens, Jr.) romance, her unwavering, somewhat overbearing relationship with her son, Jackson Avery (Jesse Williams), and her fondness for a groundbreaking case that sometimes involves a man's infected genitalia. In later seasons, Catherine also developed a Grade III chondrosarcoma, that nearly ended her life.

In Season 19, she had 95 percent of the tumor removed but was told she would have to live with the other 5 percent of her tumor for the rest of her life. However, in Season 19, her cancer progressed, and she tried using alternative measures to manage the prognosis. But in Season 15, it appears her health has continued to decline.

During the Season 21 premiere, Meredith found Catherine collapsed on her office floor while they remained at odds over Catherine wanting to fire her. In a trailer for Season 21, Ep. 2, Meredith takes her boss on as a patient and performs a CT Scan. Dr. Amelia Shepherd (Caterina Scorsone) walks in as Meredith helps her, and the doctor tells her sister-in-law, "Now's not a good time." While it's not the best time for them to chat, it is a good time for Amelia to notice Catherine's multiple tumors.

"Her scans are up," Amelia says in the trailer, adding, "and it's full of tumors."

While Amelia's assessment isn't a good sign that Catherine will remain in good health, it seems Debbie is sticking around for the long haul, which could take a while based on the show's track record. She's said that, despite Catherine's health issues, she hopes the character still has plenty of days ahead.

"I'm there as long as I am needed," Debbie confirmed to Entertainment Tonight in December 2023. "It seems like I'm still needed."

"I tell them, don't be killing me off yet," she joked. "Not yet."

Now that fans can breathe knowing Debbie's time on Grey's isn't over just yet, we can continue focusing on the callbacks from previous seasons. Season 21 marked Jesse's return as Jackson and the return of another doctor who left the show, Dr. Sydney Heron, played by Kali Rocha. During their residency years, Sydney was the perky adversary to Dr. Miranda Bailey's (Chandra Wilson) no-nonsense approach. However, she seemingly vanished after Season 4.

Sydney's return was intentional, said Grey's Anatomy showrunner Meg Marinis, to bring more levity to the show. The character was always a ray of sunshine, and Meg said her three-episode arc will provide even more exciting moments than fans remember.

"[It] is delightful and fun," Marinis told TVLine of Kali's return. "And if you’re a longtime fan of the show, it is going to be a great, great treat."

Grey's Anatomy airs new episodes on ABC on Thursdays at 10 p.m. EST.