I'd be shocked if Danny doesn't (quietly) start inquiring around about Sully's trade value. Maybe package him with our first rounder to move up in the draft. He has not shown the commitment (at least yet) needed to make the most of his talent. He's had back and foot injuries, which are tough enough for any big man but certainly extra worrisome for a man as big as Sully is.
And really... has he gotten any better? His numbers this season are virtually identical to what they were last year, and other than playing a little more not that much improved over his rookie year (a little better scoring, but rebounding's the same). He hasn't developed the outside shot, at least not with any consistency - he's not really a stretch-big.
I mean, he's certainly not a bad player, but he looks like a rotation guy (if he stays in shape and healthy) much more than he looks like a future All-Star. And he could still eat his way out of the league, like dozens of talented big men before him.
So, I think you at least LISTEN, see what his value might be this offseason. There are certainly worse moves you could make than to re-sign Bass and keep developing KO. We still need another legit 5 to pair with Zeller, but that's the case regardless of what happens with Sully.