I think based on what we've seen, you can get an idea of what the rotations will be:
Calderon
Afflalo
Melo
Porzingis
RLopez
Grant
Galloway
Early
DWill
O'Quinn
less regular minutes for: Seraphin, Vujacic, Amundson, Thomas
15th man: maybe Antetokounmpo
I think of the starters, KP and Calderon will play under 30 minutes most nights and DWill/O'Quinn and Gallo/Grant will step in to get those minutes.
It's hard to say Porzingis or Calderon haven't earned their spot since we don't see practice. Calderon has looked pretty good running the offense to me.
Grant/Galloway playing together is, to me, a major strength of this team. I do see Galloway closing out a fair number of games over Calderon.