I think he is lazy because of his conditioning. He is at his best on the offensive boards, he is a good rebounder. I think he takes threes to rest. On the screens, with his body, and he is load, he has no reason not to set good screens. I still any team based off him or KO at the defensive end is going to struggle.
On the disengagement thing, I think that is something someone who has never played professional ball would think. It is his job to play night in and night out, even when things are not going his way. He does not get the ball, boo hoo, get a rebound and put it back up. Every missed shot is a pass to a rebounder, that he has a chance to get and put back in. If he is pouting and disengaged. Then send him to the DL and put in Powell who at least tries but I doubt this it, folks. Playing in the pros is a privelege not a right, and their are plenty of guys who want to be there and will play hard if this is the case.
It may be the first time, in his career he has sat for long periods. Sully was the man in high school, he was the man in OSU, he even played last year and the year before and they let him play. Now he is accountable for his lack of effort and defense and he rides the pine at times. Stevens has picked up on his crappy D and effort and soured on him. Maybe he is playing bad to get back at him. It happens let's see if I can get the coach fired.
Maybe he is going through the adjustment that people have to do when you realize your talent will only get you so far. I hope this is case, because he has some talent. He might take D more serious, get in shape and work on his body. It would be good for him as a player and speed along his maturity and be good for him professionally.
He could be mad that Ainge did not get him a rim protector. But Zeller has been great in other regards. I think if this continues a change of venue or trade would be good for us and perhaps him.