This is what it comes down to: Why would it make sense for Utah, and why would it make sense for Boston. I'll start with Boston. Here is Boston's core:
PG - Rondo
SG -
SF - Green, Wallace
PF - Sullinger
C - Olynyk
20 million in cap space and a TON of future draft picks. Boston has a VERY nice core. So, what do they have to offer?
Humphries, Olynyk and maybe Green.
2014 pick from Brooklyn/Atl (right now #20)
2015 LAC pick (20's)
2016 unprotected 1st from Brooklyn
2018 1st from Brooklyn
So, they don't have a ton to give up. BUT, Hayward would fit perfectly in their blueprint right now. He can play the 2 or 3, can shoot (compliments Sullinger and Rondo), and good chemistry guy. Hayward fits in perfectly. And let's be honest here, odds are, if they could pry Hayward away from Utah, Hayward would be better than Green or any pick they would send. Plus, they might be able to sign him cheaper than if they went after him as a RFA.
Hayward would be perfect for Boston. Especially if Boston ended up with Wiggins or Parker or Embiid. That is a heck of a team:
Rondo
Hayward
Wiggins/Parker
Sully
Embiid/Olynyk
Plus you can add a max player (or two if you trade Green).
Boston is contending in a year or two with that team.
So, why would Utah trade Hayward? They won't get equal value back. Utah considers trading Hayward for one reason: Money. If they don't want to pay Hayward. Now, could Boston send any semblance of a package back for Hayward? Nope. UNLESS, Utah likes Burks and wants Parker/Wiggins. Then the Jazz are getting two things from Boston: Financial relief and a possible Hall of Famer.
If I am Utah, I want Green because he is a solid player and can start for you or come off the bench. I also want one great first or two so-so firsts. If I am Utah, I want the 2016 and 2018 firsts from Brooklyn. Those are great picks, because there is a chance they end up being really good picks. And if they aren't, you have two picks in 2016, 2017, 2018 and you should be very good by then, so you can use those picks on role players, trade for role players, or trade up for a key player.
I don't budge from that stance. Worst case scenario, Boston says no and I keep Hayward, a very good player. Best case scenario? Boston says yes, I get Green and sit him the rest of the year, I get Jabari, and a ton of picks and am contending really quickly.