Hill, a 12-year NBA veteran, also won the award in 2005 with Orlando. The award is determined by a vote of NBA players.
Hill has struggled with a nagging right groin injury in the first two games of the Suns' first-round series against the San Antonio Spurs. Coach Mike D'Antoni said at the Friday morning shootaround that Hill would not start but would play Friday night in Game 3.
Leandro Barbosa will take Hill's spot in the starting lineup.
The Dumars trophy is presented to the player who reflects the ideals of sportsmanship -- ethical behavior, fair play and integrity. Shane Battier of Houston finished second, followed by Brandon Roy of Portland.