Actor Tony Burton, known for his role as Tony "Duke" Evers in the Rocky movie franchise, has reportedly passed away in California. He was 78.

Burton, of Flint, Michigan, appeared alongside Sylvester Stallone and Carl Weathers in six of the Rocky films as trainer to Apollo Creed and Rocky. Prior to his film career, Burton was a professional boxer and football player.

His "Duke" Evers character trained Apollo Creed in the first two films of the series, later moving on to Rocky's team. With help from Burton's character, Rocky would go on to beat opponents like Ivan Drago and Clubber Lang.

In addition to his role in Rocky, Burton appeared in The Shining and Stir Crazy.

Burton's younger sister, Loretta "Peaches" Kelly, confirmed the star's death to Michigan Live on Thursday. He reportedly had been hospitalized out West several times over the past year for an unknown ailment.

Those health issues, Michigan Live reports, prevented Burton from seeing Creed, which features a flashback to his Evers character using footage from a previous movie.

"There's a scene in the restaurant of that movie [Creed] where his picture is on the wall," Burton's sister told Michigan Live. "We didn't talk about [Rocky] a lot."

Actor Carl Weathers, as well as MGM Studios, mourned Burton via social media following news of his death:

Prior to his death, Burton had been living in California for the past 30 years alongside his wife, Rae. Their son, Martin, passed away of a heart attack in 2014 at age 43.