In a statement released through the school, Tillman said he is taking a leave of absence to be with his mother, who has epilepsy.
"I respect both the University and the fans more now for understanding my wanting to be with my mother at this time, as her ongoing health issues continue," Tillman said. "Coach [Larry] Krystkowiak believes in putting family first, and I cannot thank him enough for allowing me to follow in his lead."
Krystkowiak called Tillman's decision to take care of family "admirable."
Tillman averaged 10.5 points and 5.3 rebounds per game last season for Utah.