Pouncey is eligible to return to the active roster but would have to miss eight weeks. He suffered the neck injury during last weekend’s loss to the Denver Broncos.
The Chargers began the year without cornerstone left tackle Russell Okung, who was placed on the non-football illness list due to a pulmonary embolism caused by blood clots he suffered during offseason work in June.
With Pouncey and Okung out, the Chargers have just one player on the starting offensive line with more than three years of NFL experience, sixth-year right guard Michael Schofield.
The Chargers filled the vacant roster spot by signing offensive lineman Ryan Groy to the active roster.
The Chargers will have a decision to make. With only two opportunities to designate a player to return from injured reserve, the Chargers will have to decide between safety Derwin James (foot), safety Adrian Phillips (broken forearm), receiver Dontrelle Inman (quadriceps) and Pouncey when those players get healthy.
A Pro Bowler in 2018, Pouncey signed a two-year, $15 million deal last season to join the Chargers in free agency after the Miami Dolphins released him in a cost-cutting move.
Just before the regular season started, Pouncey signed one-year, $9 million contract extension that keeps him with the Chargers through the 2020 season.
Pouncey was voted a team captain this season. He had not previously missed a game since joining the Chargers.