Updated

San Diego, CA (SportsNetwork.com) - The San Diego Chargers will be without running back Ryan Mathews and wide receiver Keenan Allen for Saturday's game in San Francisco.

Mathews didn't practice for the second consecutive week with an ankle injury that will keep him out of a second game in a row.

Allen also missed practice with a broken collarbone and an injured ankle.

Punter Mike Scifres (shoulder) remains out while tight end Ladarius Green (concussion/ankle) and defensive tackle Corey Liuget (ankle) are questionable to play.

Quarterback Philip Rivers (chest/back) and nose tackle Ryan Carrethers (elbow) are good to go.