Shemar Moore Pens Heartfelt Tribute to 'Young and the Restless' Co-Star Kristoff St. John

Shemar Moore is continuing to mourn the loss of his The Young and the Restless co-star Kristoff St. John.

The S.W.A.T. star took to Instagram Sunday to pen a touching message to the late actor, who passed away on Feb. 3 at the age of 52 from hypertrophic heart disease by way of alcohol abuse.

St. John had portrayed Neil Winters on the CBS drama since 1991.

"KRISTOFF ST JOHN ...... SHUGGIE BOOGIE.... MOE DIGGITY.... MY ANGELS FOR LIFE!!!" Moore captioned the post, also mentioning his two bulldogs who passed away last week just days apart. "My heart HURTS and I will get the tears OUT!!!"

"Thank You ALL for showing me what UNCONDITIONAL LOVE, LOYALTY, and BROTHERHOOD feels like... You helped me become the Man that I am today!!!" he continued. "NEVER forgotten.... ALWAYS remembered and Appreciated!!! I MISS YOU!! I LOVE YOU!!! I will think of you EVERYDAY... and... SMILE. enough rain.... LET THE SUN SHINE."

Following St. John's death, the former Criminal Minds actor, who appeared as St. John's on-screen brother Malcolm Winters from 1994 until 2014, shared a video on Instagram in which he promised to "celebrate all your good" in the wake of his passing.

"I lost my brother yesterday," he said. "I never had a brother, but you were my brother. You showed me the way. You were my mentor, you were my inspiration. You showed me what true talent was. You showed me what humility was. I love you. I hate this. I love you, but I'm going to celebrate all your good."

"To my Young and Restless family, Kristoff St. John aka Neil Winters, celebrate this man, the most popular, iconic black man in soap opera daytime history," he continued. "Give him that. He earned it."

"To his personal family, Mia, Alana, his current fiancée, his son Julian, Paris, Lolacry your tears. I'm crying right along with you, but we're gonna celebrate his heart, celebrate his goofy ways, celebrate his talent. He loved you. He loved us," he concluded. "Kristoff, sleep, man, find your peace."

Moore is expected to reprise his role as Neil Winters' half-brother for a week-long storyline paying tribute to the late actor and his Young and the Restless character. Moore will join actors Victoria Rowell (Drucilla Winters), Mishael Morgan (Hilary Curtis Winters), and Christel Khalil (Lily Winters) for the two-episode storyline, airing April 25 and 26, as well as a tribute episode on April 29.