The former Celtics forward, who had been playing for the Idaho Stampede of the NBA Development League, announced his retirement in the locker room Saturday night, according to the team.
Walker, who played 12 seasons in the NBA, is reportedly expected to make a formal retirement announcement in the coming days.
The 35-year-old's most notable playing days came as a member of the Celtics from 1996-2003. He was named an All-Star three times while forming a potent duo with Paul Pierce.
Walker, who won an NBA championship with the Heat in 2006, also played for Atlanta, Dallas and Minnesota. He averaged 17.5 points and 7.7 rebounds per game over the course of his career and averaged a career-high 23.4 points per contest with the C's in 2000-01.
Walker last played in the NBA with the Timberwolves during the 2007-08 season and has since made headlines for his financial troubles.
