Dennis Johnson, a five-times All-Star who won three NBA titles, died from a heart attack aged 52 on Thursday. Johnson collapsed after leading a practice session for NBA Development League team the Austin Toros.
"He passed away this afternoon. This is a big loss for us," Toros vice president of sales Rick Epstein said.
One of the NBA's all-time great defensive guards, Johnson won a title with the Seattle SuperSonics in 1979 when he was named the final's MVP and two with the Boston Celtics in 1984 and 1986.
Averaging 14.1 points a game in a 13-year career including spells in Seattle, Phoenix and Boston, Johnson retired in 1990 as only the 11th player in NBA history to score more than 15,000 points and dish out 5,000 assists.
"Whether he was leading his teams to NBA championships or teaching young men the meaning of professionalism, Dennis Johnson's contributions to the game went far beyond the basketball court," NBA commissioner David Stern said in a statement.