I'll agree with Jackson and Mickey being the odd men out.
But I've watched Zizic for 3 SL games now, and I can't see for the life of me how he's ready for the NBA. He's never ahead of the play, seldom engaged in real time, and always a step or two behind. His reaction time starting from the jump of the ball is late. I guess it goes to show you how desperate the Celtics are for size. He clearly needs another year of seasoning.
In fact as I look at what looks like the entire team on paper, the end of the bench is really a developmental situation. IMO Danny is looking to develop some of the young assets quickly, because of having some many I guess, rather than go with more established players like Jerebko, and Green.