I believe McCollum is the best player we can realistically get this offseason.
Blazers in: Marcus Smart + Evan Fournier (signed and traded to the Blazers)
Celtics in: CJ McCollum
We'd have to somehow dump Kemba in a different trade. I mean, Kemba and CJ playing together would be a defensive nightmare.
Why for the Blazers
Imo, Smart is the 2nd most versatile/switchable guard defender in the NBA behind only Ben Simmons (who ain't exactly a guard to begin with). He'd be a nice fit next to Lillard.
Fournier would operate as a secondary shot creator. He can create his own shot. He can create shots for his teammates as well. He can ever run the PnR a little bit.
PG: Lillard
SG: Smart
SF: Fournier
PF: Covington
C: Nurkic
6th man: Powell
Problem is, the Blazers would become hard capped at the apron. If they cannot retain Powell (assuming he opts out), then it's a bad trade for them. Not sure what Powell and Fournier will command on the open market.