Williams (ankle) missed practice for the second day in a row Thursday, Eric Branch of the San Francisco Chronicle reports.
San Francisco coach Kyle Shanahan also told radio station KNBR that Williams is "in jeopardy of not playing" Sunday against the Packers, per Branch. The left tackle battled through last Sunday's 20-17 loss to the Seahawks but came away from the game with soreness related to his ongoing ankle issue. Williams has started all 10 games this year for the 49ers.