The Chargers have placed four players ? tight end Antonio Gates, center Nick Hardwick, fullback Andrew Pinnock and linebacker Anthony Waters ? on the ?Active-Physically Unable to Perform? list. All four players remain on the team?s 80-man roster; however, each is ineligible to participate in practice until they pass a physical. The players can remain on the ?Active-PUP? list until the final roster cutdown date on Aug. 30. Gates is recovering from a toe injury. Hardwick is recovering from a foot injury while Pinnock and Waters are both recovering from knee injuries.