These Castle Costars Aren't Sure If They're Coming Back for Season 9 Either

Jon Huertas and Seamus Dever have not been asked back, Huertas revealed on Twitter

Castle is already losing one of its biggest stars should the show find itself renewed for a ninth season—but it could return minus a few more familiar faces.

Jon Huertas and Seamus Dever, who play everyone's favorite cop duo, Esposito and Ryan, haven't been asked to come back yet, Huertas revealed in a series of tweets about the shocking news that Stana Katic and Tamala Jones, both of whom have been with the series since the beginning, are not coming back to the show even if it is renewed.

"Who knows what ABC has in store at this point. @seamusdever & I haven't been asked back yet either… Uh oh. #NothingIsAsitSeemsAnymore," he wrote after the news broke.

Huertas also said he was devastated to lose his two costars. "To say I'm sad about @Stana_Katic & @tamalajones not coming back even if #Castle returns would be a gross understatement. #blownaway #morose," he wrote, adding, "If there's a S9 of #Castle, I hope that r fans can see it fit 2 support this unknown incarnation of the show. And if I'm a part of the cast, I'll work hard 2 continue 2 keep the integrity of our show intact… #ConsiderThis #400JOBS And I am gonna miss @Stana_Katic & @tamalajones who are more than coworkers to me but dear friends. #Heartbroken."

Even worse? He and costar Toks Olagundoye both learned of the news online. "What else is sad???!!!! That I have to find this out online!!! This is my family! Why couldn't someone have told me #InADifferentWay ?!," Huertas tweeted, with Olagundoye saying, "Ok...... So, here's the thing: I know NOTHING. The info I have I have from @Deadline. Believe you me I wish I knew more."

Dever also posted a tribute to his costars, writing, "Oh man. @Stana_Katic has been a good partner and a good friend for the last eight years. Thank you, Stana. And @tamalajones is such a good actor. We haven't seen 1/10th of what she can do. Can't wait to see what role she does next."

Susan Sullivan, who plays Castle's mother, Martha Rodgers, also weighed in on Twitter. "Surprised and saddened to hear @Stana_Katic @tamalajones are moving to other artistic pursuits change allows growth," she wrote.

There's no official word on Nathan Fillion's future with the show, but Deadline reports he'll likely return should ABC officially order a ninth season.

Castle airs Mondays at 10 p.m. on ABC.