IMHO:
Gaines, Joyner and Mo Alexander are shoo ins at this point, imho. All can cover. All can tackle. All hustle. All will be solid @ special teams.
Cody Davis will make the team for the exact reasons stated by
@RamWoodie (and others who he echoes). The only thing that could keep him off the team is if Bryant really flashes in one of these pre-season games, but I think he's destined for the practice squad. But of course, Davis was on the practice squad last year too, so these late round rookies and UDFAs should just keep their noses down, learn well, play hard and they'll get their chances.
I'm at 5 CB and 4 S, which is a happy place to start if for no other reason than because Joyner plays safety at a high level.
4+ Ss :McLeod, TJ McD, Mo Alexander, Davis, Joyner in a pinch
5 CBs: Jenkins, Tru Jo, Joyner, McGee, Gaines
The last guy could be either imho, but exactly as
@CoachO says, the guy will have to be a willing and able special teams guy to make the 53 or have any chance at the 47. Woodard (imho) seems to have the inside track, but things can change fast.