I'm not saying it's going to happen, but we do need to realize that this isn't a normal #2 pick. Firstly, it's not a relatively highly valued draft. Secondly, as everything has been with Golden State for the past few years, the team owning the second pick currently is an anomaly for that situation.
That being said, it's hard to imagine Ball being the main target of a potential trade there. Maybe he slips to 7-10 and the Celtics have options in that range?