"We think he'll play, but that's up to the doctors," Lynn said, per ESPN. "That's not my decision."
The veteran quarterback must be cleared by an independent neurologist before he's allowed to play again.
NFL Network Insider Ian Rapoport reported Wednesday that the Chargers were encouraged by the progress Rivers had made under protocol and there was optimism he would play Sunday. For a 3-6 team on the edge of falling into the abyss of another failed playoff bid, having Rivers under center could be vital for preserving the Chargers' postseason hopes.