Raiders coach Jon Gruden isn't sure if he has a backup quarterback on his roster.

Gruden was asked Friday after the Raiders' 13-6 preseason win over the Packers if Oakland currently has a backup quarterback on its roster, and he wasn't willing to give a direct answer.

"I don't know," Gruden told reporters after the game. "You know, we're going to continue to work, continue to see who's available. I thought there were some good moments tonight, and there were some moments tonight that weren't good. It's been too inconsistent, but I'm not going to say much more tonight until I see the tape, but we're going to continue to evaluate it."

The Raiders know Derek Carr will be their starting quarterback. But there's still some questions as to who his backup will be based on EJ Manuel's and Connor Cook's preseason performances.

Cook played most of the first half Friday and completed just six of 15 passes for 72 yards with one interception. Manuel struggled with ball security and fumbled scrambling for a first down.

The Raiders have one more preseason game, Aug. 30 against the Seahawks, where Cook and Manuel have the opportunity to prove themselves for the job.