I think Danny's gonna go after AD whether or not Kyrie is coming back.
Smart - Brown - Hayward - Davis - Horford
That team plus the right supporting pieces could be a heck of a defensive team. If Hayward gets anywhere close to where he was in Utah, maybe they have enough shot making to be a real threat in the East.
Anyway, I think Ainge is going for it. He didn't come this far just to give up because Kyrie turned out to be a sourpuss weirdo.