I don't think I'd pursue it, but in theory:
MEM19, Morris, Yabusele, Nader to LAL
Ball, LAL20 to BOS
Follow-up trade, Rozier for a 1st rounder.
So we'd swap Rozier for 4 years of control of Ball, and he can backup Kyrie this year. We swap MEM19 for 2 future 1st rounders in 2020 or later. Makes sense as we don't really have room for multiple 1st rounders next summer. Also saves us a couple million in cap room.