The team currently has 15 players under contract, so technically all of the unguaranteed contracts can stay. Anyway, Pressey will probably be the last of these to be waived -- not because he's played particularly well, but because Johnson and Babb are both worse and more redundant.
I can, however, easily see a scenario where they waive all three of them if they can bring Bayless, Humphries, and Iverson in for a reasonable price.
I don't expect anyone else to get moved. No, not even Bass, and definitely not Green.