Williams was considered a high-risk close contact of AJ Dillon, who tested positive for COVID-19 on Monday, and won't play Thursday at San Francisco, Tom Pelissero of NFL Network reports.
Any player deemed "high risk" must self-isolate for five days before having a chance to return to team facilities, meaning Williams will be away from his teammates until at least Saturday. Now down both Williams and Dillon for Thursday's NFC matchup, the Packers will evaluate how No. 1 RB Aaron Jones is coming along in his recovery from a strained calf to determine if a return is possible. Aside from Jones, the only healthy running backs in Green Bay are Tyler Ervin and practice squad member Dexter Williams.