USA Today confirmed St. John's final episode of the show will air Wednesday at 12:30 p.m. ET. The actor had played Neil Winters on the CBS series since 1991.
St. John was found dead Sunday at his home in the San Fernando Valley in California. He was 52 years old.
"The news of Kristoff St. John's passing is heartbreaking," CBS and Sony Pictures Television said in a joint statement Monday. "He was a very talented actor and an even better person."
"For those of us who were fortunate enough to work with him on The Young and the Restless for the last 27 years, he was a beloved friend whose smile and infectious laugh made every day on set a joy and made audiences love him," the companies added.
St. John's Young and the Restless co-star Shemar Moore, who portrayed Winter's half-brother, Malcolm Winters, mourned the actor's death in a statement to People the same day.
"I'm raised an only child, but Kristoff is truly the closest thing to a brother and a brother's love and a brother's mentorship that I've ever known," the star said.
"He didn't have to embrace me the way he did," he added. "He just saw me and he embraced me like a brother. If he hadn't embraced me, I would have never got my sure footing in the beginning days."
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Notable deaths of 2019