"Rivers played the entirety of the Chargers' 21-12 loss to the New England Patriots with a right knee with no ACL. He revealed Monday he had arthroscopic surgery last Monday to clean out loose cartilage and enable him to play. "If I don't do that Monday, I had no chance of playing," Rivers said. The San Diego Union-Tribune first reported Friday that Rivers had injured his ACL, but the extent of the injury was not known until today. "The ACL is gone," Rivers said."