James Michael Tyler, who played the deadpan, smitten barista Gunther on the TV show “Friends,” died on Sunday at his home in Los Angeles. He was 59.

His manager, Toni Benson, said the cause was prostate cancer, which was diagnosed in September 2018. After his diagnosis, Mr. Tyler shared his story to encourage others to get screened for prostate cancer as early as 40.

“Friends” helped launch the careers of its star-studded cast, which included Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc, Matthew Perry and David Schwimmer. It debuted on NBC in the fall of 1994, ran for a decade, and typically had around 25 million to 30 million viewers each week.

Though Mr. Tyler was not a main character, he was widely considered to be “the seventh friend” and appeared in 150 episodes. He played the part of Gunther, a barista at Central Perk, the friends’ hangout, who had a deep crush on Ms. Aniston’s character, Rachel, who also worked at the coffee shop.

Mr. Tyler’s path to the show was fortuitous. While working as an actual barista at a real-life coffee shop, he was asked if he would be interested in being an extra on “Friends.” For the first season, his character was known as “Coffee Guy.”

“At the time I was also working as a barista for a place called the Bourgeois Pig, one of the last independent coffee houses in Los Angeles,” Mr. Tyler told The New York Times in 2012. In his second season, he got a line of dialogue: “Yeah,” he said, when Mr. Schwimmer’s character, Ross, asked him if his apartment had stairs.

Marta Kauffman and David Crane, the show’s co-creators, recalled the beginnings of Mr. Tyler’s run on the series.

“When he started as an extra on Friends, his unique spirit caught our eye and we knew we had to make him a character,” they said in a statement Sunday night. “He made Gunther’s unrequited love incredibly relatable.”

In the series finale, Gunther, known for his bleached locks, finally summoned the courage to confess his love to Rachel, who let him down warmly.

“I love you, too,” Rachel told Gunther. “Probably not in the same way. But I do. And when I’m in a cafe having coffee, or I see a man with hair brighter than the sun, I’ll think of you.”

Born May 28, 1962, in Winona, Miss., Mr. Tyler was the youngest of five children, raised by a retired Air Force captain and a homemaker, according to a biography on IMDb. He moved to Anderson, S.C., to live with his sister at age 11 and enrolled at Clemson University as a geology major. He earned a master’s of fine arts from the University of Georgia and moved to Los Angeles after a brief stint of selling cars in Olympia, Wash., according to the bio.

“Michael loved live music, cheering on his Clemson Tigers, and would often find himself in fun and unplanned adventures,” Ms. Benson said in a statement. “If you met him once you made a friend for life.”

Mr. Tyler revealed publicly in June that he had prostate cancer. He told “Today” that he was surrounded by an “extraordinary” support group and that many people were praying for his health.

“It’s made me, personally, just realize how important every moment is, every day,” Mr. Tyler said. “And fighting. Don’t give up. Keep fighting. Keep yourself as light as possible. And have goals. Set goals. My goal this past year was to see my 59th birthday. I did that, May 28th. My goal now is to help save at least one life by coming out with this news.”

While undergoing treatment, Mr. Tyler continued to perform and starred in two short films, “The Gesture and the Word” and “Processing,” earning accolades at film festivals, according to The Hollywood Reporter.

Mr. Tyler’s survivors include his wife, Jennifer Carno. A complete list of survivors was not immediately available.