Tony Burton, a veteran character actor best known for brief but memorable turns as a tough, no-nonsense trainer and cornerman in Sylvester Stallone’s first six “Rocky” films, died Feb. 25 at a hospital near his home in Sun City, Calif. He was 78.

The cause was pneumonia, said his wife, Aurelain “Rae” Burton.

Failing health had prevented him from appearing in “Creed,” the seventh “Rocky” movie and the one for which Stallone was nominated for a best supporting actor Oscar at this year’s Academy Awards.

Mr. Burton, a former boxer, had a long career as a character actor. He appeared in the thriller “The Shining” and the comedy “Stir Crazy” (both in 1980) and was one of the ballplayers in the 1976 film “The Bingo Long Traveling All-Stars & Motor Kings,” about a black baseball team.

He was a regular in the television series “Frank’s Place” and appeared in “Chicago Hope,” “The Rockford Files” and “Sanford and Son.”

Actors Tony Burton and Sylvester Stallone in 2006. (Frazer Harrison)

His last major film was 2006’s “Rocky Balboa,” in which he prepares the nearly 60-year-old Rocky Balboa character played by Stallone for an exhibition against the current champion, telling Balboa to “bring some hurtin’ bombs.”

In the first two Rocky films, his character, Tony “Duke” Evers, was trainer and manager to Rocky’s world-champion opponent, Apollo Creed, played by Carl Weathers.

In “Rocky II,” Mr. Burton tries to talk the champion, who barely won that first fight, out of giving Balboa a rematch.

“He’s all wrong for us, baby,” his character says. “I saw you beat that man like I never saw no man get beat before and the man kept coming after you. . . . Let it go.”

Anthony Mabron Burton was born in Flint, Mich., on March 23, 1937. He was a top Golden Gloves boxer in his youth and had a brief professional boxing career.

He served more than three years in a Chino, Calif., prison for robbery, and the acting exercises he performed as part of a therapy program helped steer him to a new profession after his release.

“Prison for me was productive because I applied myself while I was there,” he told an interviewer in 1988. “I got my high school diploma and a degree from the University of California. But most important, I got myself together and found out who I was and how I could proceed without destroying myself.”

He began working with small theater groups in Los Angeles, and he shared an agent with Weathers, who brought Mr. Burton to the attention of “Rocky”’s producers.

Besides his wife of 36 years, he is survived by three children; a stepdaughter; four brothers; and four sisters, the New York Times reported. A son died in 2014.

— Associated Press