There's a reason Gruden cut him from the Bucs, and that is that Rob Johnson tends to hold onto the ball and run when he should really be looking to unload the ball out of bounds. As a result, he gets sacked alot and loses a lot of yardage. I think Spurrier figured that out earlier this year, too, which is why Johnson was available for the Raiders. Heck, maybe the Raiders will make him a running back that throws, instead of a quarterback that runs.
I guess it all just proves that Flutie should've been the starter at Buffalo all those years ago, instead of Johnson.