Burt Young, the Oscar-nominated actor who played Paulie, the rough-hewn, mumbling-and-grumbling best friend, corner-man and brother-in-law to Sylvester Stallone in the “Rocky” franchise, has died.

Young died Oct. 8 in Los Angeles, his daughter, Anne Morea Steingieser, told the New York Times on Wednesday. No cause was given. He was 83.

Young had roles in acclaimed films and television shows including “Chinatown,” “Once Upon a Time in America" and “The Sopranos.”

But he was always best known for playing Paulie Pennino in six “Rocky” movies. The short, paunchy, balding Young was the sort of actor who always seemed to play middle-aged no matter his age.

When Paulie first appears in 1976's “Rocky,” he's an angry, foul-mouthed meat packer who is abusive to his sister Adrian (Talia Shire), with whom he shares a small apartment in Philadelphia. He berates the shy, meek Adrian for refusing at first to go on a Thanksgiving-night date with his buddy and co-worker Rocky Balboa, and destroys a turkey she has in the oven.

The film became a phenomenon, topping the box office for the year and making a star of lead actor and writer Stallone, who paid tribute to Young on Instagram on Wednesday night.

Along with a photo of the two of them on the set of the first film, Stallone wrote “you were an incredible man and artist, I and the World will miss you very much.”

“Rocky” was nominated for 10 Oscars, including best supporting actor for Young. It won three, including best picture. Young and co-star Burgess Meredith, who was also nominated, lost to Jason Robards in “All the President's Men.”

As the movies went on, Young's Paulie softened, as the sequels themselves did, and he became their comic relief. In 1985's “Rocky IV” he reprograms a robot Rocky gives him into a sexy-voiced servant who dotes on him.

Paulie was also an eternal pessimist who was constantly convinced that Rocky was going to get clobbered by his increasingly daunting opponents. His surprise at Rocky’s resilience brought big laughs.

“It was a great ride, and it brought me to the audience in a great way,” Young said in a 2020 interview with Celebrity Parents magazine. “I made him a rough guy with a sensitivity. He’s really a marshmallow even though he yells a lot.”

Born and raised in Queens, New York, Young served in the Marine Corps, fought as a professional boxer and worked as a carpet layer before taking up acting, studying with legendary teacher Lee Strasberg at the Actors Studio.

On stage, in films and on television, he typically played small-time tough guys or down-on-their luck working class men.

In a short-but-memorable scene in 1974's “Chinatown,” he plays a fisherman who throws a fit when Jack Nicholson's private detective Jake Gittes shows him pictures proving his wife is cheating on him.

Young also appeared in director Sergio Leone's 1984 gangster epic “Once Upon a Time in America” with Robert De Niro, the 1986 comedy “Back to School" with Rodney Dangerfield, and the 1989 gritty drama “Last Exit to Brooklyn” with Jennifer Jason Leigh.

In a striking appearance in season three of “The Sopranos” in 2001, he plays Bobby Baccalieri, Sr., an elderly mafioso with lung cancer who pulls off one last hit before a coughing fit leads to him dying in a car accident.

He guest-starred on many other TV series including “M(asterisk)A(asterisk)S(asterisk)H,” “Miami Vice” and “The Equalizer.”

Later in life he focused on roles in the theater and on painting, a lifelong pursuit that led to gallery shows and sales.

His wife of 13 years, Gloria, died in 1974.

Along with his daughter, Young is survived by one grandchild and a brother, Robert.