Coach Larry Drew announced before the team's 102-86 loss Monday night to the Boston Celtics that he was told earlier in the day that Sanders was injured when he was elbowed in the right eye by Houston's James Harden as the two went for a rebound early in Saturday night's game.
Drew believes the fracture is in the orbital bone, and added that Sanders is experiencing double vision in the eye.
Sanders missed nearly two months early this season after tearing a thumb ligament in a fight at a Milwaukee night club.
Zaza Pachulia started in Sanders' absence against Boston.
Information from The Associated Press was used in this report.