Jason Collins, the former NBA player who became the first openly gay man to play in a major US pro sports league, is undergoing treatment for a brain tumor, the league said in a statement on his behalf on Thursday.

"NBA Ambassador and 13-year NBA veteran Jason Collins is currently undergoing treatment for a brain tumor," the statement said.

"Jason and his family welcome your support and prayers and kindly ask for privacy as they dedicate their attention to Jason's health and well-being."

Collins, 46, played 13 seasons in the NBA, the first seven with the Nets in New Jersey. He capped his career with the Nets after their move to Brooklyn.

He also spent time with the Atlanta Hawks, Boston Celtics, Memphis Grizzlies, Minnesota Timberwolves and washington Wizards, averaging 3.6 points and

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