The Chargers placed Webb (knee) on injured reserve Friday, Gilbert Manzano of The Orange County Register reports.
Webb underwent a knee procedure before being placed on injured reserve, but coach Brandon Staley said he expected him to return this season. With Webb out for at least three weeks and Alohi Gilman dealing with a quadriceps injury, the Chargers are extremely thin at safety behind Derwin James and Nasir Adderley.