Because Bruce is trying to solidify his leadership core and getting his players to buy into a young Petey as the leader of this team.
I love Miller, but he doesn’t have the talent that Petey does. Nor does Boeser or Horvat.
Those players need to understand that Petey is the team’s future and present best player.
The rest of the team needs to build and play around Petey.
Bruce is simply making a point, in my opinion, by keeping Petey back.
He’s basically saying, “If you guys think you’re better, then go out there and show it/prove it”.
“If not, then play around Petey, and stfu”.
I think a lot of egos need to be checked in order for the team to be a ‘team’.