"He's progressing," Staley told reporters. "Just felt like resting him this week would be the best course of action."
Williams suffered the injury in Week 7 and reaggravated it on the third play of Sunday's loss to the Kansas City Chiefs. He was unable to finish the game and did not practice this week.
The Chargers (5-5), who are on the outside of the AFC playoff picture, also could be thin in the secondary while facing Cardinals quarterback Kyler Murray, who is expected to return from a hamstring injury that sidelined him for two games.
Staley said that he expects Davis to be available but that Adderley seemed unlikely.
"I don't think he can grip his hand the right way to be able to tackle and get guys on the ground," Staley said.