I am a little confused.
Didn't the C's just make a deal with Cleveland, sending Luke and Semih for a future second round pick? If Cleveland didn't want Powe and the C's did want Powe, why wasn't he just included in the deal? This doesn't make sense to me.
It's a good question. The salaries would have matched up. Two possibilities come to mind:
1. Ainge made the deal simply to open roster spots, and it was more about getting the Minnesota second rounder back from Cleveland. If they had asked for Powe back, the Celtics would not have gotten the pick as well in return.
2. Ainge wanted to force the Cavs to cut a player from their roster. Perhaps he thought it might be Parker, perhaps he calculated it would be Powe. It turned out to be Powe, and now that the Celtics have the open roster slots, they will look into signing him. If they do, it will be at a cheaper price tag than had they traded for him.