Harris suffered the injury midway through the third quarter of Sunday's loss to the Carolina Panthers and was out the rest of the game. The team did not put a timetable on how long he'd be out, but he will miss at least the next three games by being on injured reserve.
He had played every defensive snap up until the injury and was considered integral to the Chargers' secondary.
Harris joined the Chargers via free agency last offseason after spending nine seasons in Denver, where he made four Pro Bowls and won a Super Bowl.
The Chargers (1-2) appear to be without eight starters now because of injury.