I don't think there's a single player who should be here without a doubt next year. Any of them can be packaged in a trade to make this team better. I would say, though, that I agree with Bayless, DeRozan, Davis, Johnson, and Bargnani
if you can get the right pieces around him and he is in the right role. That's not a bad core going forward, particularly if those players can fulfill their potential.