Not only is Avery Bradley on a better contract (8.2/8.8 vs 9.9/10.5/11.2), he is capable of playing the 1 (insurance in the event that Exum doesn't return to 100%), is one of the best perimeter defenders in the NBA, shot .361% on 5.8 3PA (per 36) last season, & has missed a total of 11 games over the last 2 years.
Don't get me wrong, I like Burks & his potential as much as the next fan but his inability to stay on the court looks like it could become a reoccurring problem. The guy has amazing potential as a slasher/scorer, but Avery Bradley (IMO) would better fit this team due to his style of play, hustle/defensive aggression, & positional versatility.
Exum undoubtedly has the potential to develop into a similarly elite defender but acquiring Bradley would not only provide us with insurance (in the event that he doesn't), he would also provide us with the potential to have 2 elite defenders locking down the perimeter for 48 straight minutes (which in return would make the interior defensive presence of Favors & Gobert that much more effective).
I still have hope that Burks can develop into that instant-offense, elite bench scoring, sixth man candidate of the year that he's shown the potential to have, but swapping him for Bradley is a no brainier (IMO). Giving up the #12 pick to do so is an entirely different story, but I wouldn't hesitate to give up the OKC/GSW 1st to get it done. Bradley is the type of player who's impact on the game doesn't show up in the box score & who's influence on the team goes far beyond just his play on the court.
I don't know if BOS even considers trading him right now but that could change with Marcus Smart developing into a similar player, Terry Rozier/RJ Hunter needing more developmental time, & the possibility of BOS drafting another guard with one of their many picks in the upcoming draft. But the main reason I don't see this happening is that I don't believe BOS would be looking for a guard in return if they were to trade Bradley.