Fuller can play free safety (as can Burgess). David Long Jr. will replace Hill. Floyd is the tougher guy to replace. If he gets too pricey, we could sign another "prove it" vet. I could say Lewis replaces Floyd, but I don't trust his health. I'm not worried about S or CB. You're saying we can't be sure of what we have. Well, every team is in that boat with replacements. Burgess looked damn good before he went down. Rapp can play. And Long Jr. has shown good and bad. But we spent a 3rd round pick on him for a reason. When Ramsey missed the Miami game, our pass defense held up just fine with Long playing over 75% of the defensive snaps. Ramsey is a much bigger loss than Hill.
I should also note that Terrell Burgess can play both S and SLCB. So if we slide Fuller to FS and Rapp wins the SS job, Burgess could also potentially replace Hill if Long doesn't win the role. We'll need to draft another CB and/or S for depth, but we'll be okay.