Former American basketball player Jason Collins, who in 2014 became the first active athlete in a major league in the United States to openly reveal his homosexuality, is suffering from a brain tumor, the NBA announced Thursday.

"NBA Ambassador and 13-year NBA veteran Jason Collins is currently undergoing treatment for a brain tumor," the North American Basketball League said in a statement. "Jason and his family appreciate your support and prayers and ask that you respect their privacy so they can fully focus on his health and well-being."

The 46-year-old former center spent thirteen seasons on the NBA court, including eight with the New Jersey/Brooklyn Nets. He also played for other franchises in Atlanta, Boston, Memphis, Minnesota, and Washington, for a total of 735 games.

Collins, who retired in November 2014, came out as gay in an article published by Sports Illustrated in April 2013. "I'm a 34-year-old NBA center. I'm Black and I'm gay," he wrote. "I didn't set out to become the first athlete in a major sport in the United States to come out. But now that I've come out, I'm happy to start the conversation."

He was then without a club but later joined the Brooklyn Nets, with whom he played again on February 23, 2014, becoming on that day the first openly gay player to participate in a game in one of the four major leagues in the United States (NBA basketball, NHL hockey, NFL football and MLB baseball).

"We send our deepest love and support to Jason Collins and his family," the Nets tweeted on X.