The Big East Conference school announced the death Tuesday without identifying a cause. The New York Post quoted former teammate and friend Lamont Middleton in reporting that Green's death was related to the coronavirus.
A New York City native, Green played for St. John's from 1991 to '94, playing his first season under Lou Carnesecca and his final two for Brian Mahoney. He averaged 2.3 points.
"He was a very gifted athlete, very strong," Mahoney said. "He was a guard who could penetrate. He had very good skills penetrating, dribbling the ball and became a very good defensive player for us."
Green maintained a close relationship with the program over the years, attending games as recently as this past season.
"He was our defensive lockdown guy," Ron Lifonte, St. John's assistant athletic director for sports medicine, told the New York Post. "He could score if he needed to. He was one of the guys who really relished the role of `Give me your best player and I'll lock him down.' He sacrificed his offense a lot for the good of the team, and he was everybody's favorite."
Current coach Mike Anderson called Green's death a loss for the St. John's family.
"He left behind a lasting legacy with his contributions to our basketball program and touched so many lives in his years of service as a police officer in New York City," Anderson said.
The university did not provide information on survivors or funeral arrangements.