Charlie Whitehurst

Backup quarterback Charlie Whitehurst stood on the sideline, his left knee wrapped in ice.

Whitehurst would downplay his injury afterward, but there was enough concern that the Chargers began making calls around the league, sending feelers to potential replacements, sources said.

Billy Volek naturally jumps out as possible candidate. He spent the past five years as a San Diego backup and remains a free agent after his March release.