Williams (foot) has yet to advance past individual work, Hayden Cilley of ClutchPoints.com reports.
Williams hasn't played since March 3 due to a stress reaction in the third metatarsal of his left foot, and he'll need to participate in 5-on-5 work before being cleared to return. The big man can be considered doubtful for Saturday's game against the Jazz until the Suns offer an update on his progress. Oso Ighodaro will likely continue to start for as long as Williams is sidelined.