How much better of a 4th CB can you get though? He'd have to be at the right price, but I think he's the kind of guy you get to be your 4th CB.
Yeah as a 4th CB you're asking a guy to stay ready and come in for a spot start or a few minutes of the bench when needed. A guy with the experience of Hernandez would lead you to believe he can do that kind of job. He's in the twilight of his career but we wouldn't be asking him to play starter minutes this season.