Wizards coach Randy Wittman says Wall won't play Monday night because of an injured left hand and wrist.
Washington leads the best-of-seven series 2-1 heading into Game 4.
Wall has five non-displaced fractures in his non-shooting hand and wrist. He was hurt in Washington's Game 1 victory at Atlanta.
He missed Game 2, which the Hawks won, and Game 3, which the Wizards won on Paul Pierce's 21-foot jumper at the buzzer.