Shaquille O'Neal announced on Twitter that he is retiring after 19 seasons in the NBA.
The 15-time All-Star signed a two-year deal with the Boston Celtics last summer, but he was only able to play in 37 games in the regular season due to an Achilles injury.
According to Jackie MacMullan of ESPN, Celtics spokesman Jeff Twiss said that O'Neal hasn't informed the team of his plans.
O'Neal was selected with the first overall pick in the 1992 draft by the Orlando Magic.
The Diesel is 5th all-time in career points with 28,596. He won the 1993 Rookie of the Year award and the 2000 NBA MVP.
The 39-year-old won three NBA titles with the Los Angeles Lakers and one with the Miami Heat. He also played for the Phoenix Suns, Cleveland Cavaliers and Boston Celtics.