Gradkowski was hit hard by San Diego's Shaun Phillips on a pass play in the final minute of the first quarter Sunday. The play was originally ruled a fumble. The Raiders challenged and it was changed to an incomplete pass.
Gradkowski went to the locker room and was replaced by former starter Jason Campbell. The Raiders originally said Gradkowski would not return but he came out to start the second half. He threw two incompletions on one drive and then was replaced again by Campbell.