I mean, typically, 2nd rounders could net you rentals like Tyreke Evans and Lou Williams, or others too. But if I'm not mistaken, the Celtics don't have 2nd round picks coming the next few years, since that pick likely goes to OKC in 2018, and MEM in 2019 if it conveys between 56-60 (which seems likely, and isn't a bad thing).
And the C's likely aren't giving up their 2018 own first round pick for a pure rental I imagine either.
So.. what can they even offer to acquire a Tyreke Evans or Lou Williams?
No, they aren't trading Smart or Rozier, and I already went over the whole draft picks "dilemma" above.
I'm guessing Ainge is simply going to see all the players that get bought out and use the DPE to sign whoever the "best available" guy is (My guess, either Chandler or Monroe from the Suns, depending on who they buy-out).