Westphal died after a battle with brain cancer, according to USC, where he played from 1969 to 1972. His wife, Cindy, and his two children and grandchildren survived.
Westphal was drafted by the Boston Celtics as the tenth choice for the 1972 NBA Draft, according to the USC. He won the NBA title with the Celtics in 1974.
After his playing career, Westphal entered training, starting in many small colleges. His 1988 Grand Canyon College team won the NAIA National Championship. Then he moved to the NBA as an assistant coach with the Suns.
He spent 10 seasons as head coach of three different NBA teams, including the Suns – which he coached to the NBA Finals in 1993 – Supersonics and the Sacramento Kings.
“His toughness, skills and intellect made him a major contributor to the 1974 Boston Celtics Championship team,” said Silver, “and he’s a constant star with the Phoenix Suns.”
“His generosity, leadership and love for the game, which defined his many years in the NBA, will be remembered,” Silver added. “We extend our deepest condolences to Paul’s wife, Cindy, and her family.”
CNN’s Dakin Andoni contributed to this report.