Pretty sure PG13 is a UFA, so it would just be a matter of managing the cap. Of course, he is a max player, so getting him will probably mean parting with both Baze and THJ. I think Bud already prepared for that possibility when he drafted Bembry and Courdinier, and got Dunleavy before the trade deadline, and he'll probably look at more guards in this year's draft.
This is it though. We get PG13, it's between us and the Cavs in the East. Even if we lose THJ, we still have solid role players in Dunleavy and Ersan Ilyasova (who I forgot to add earlier).
EDIT: Never mind, PG13 still has one year left on his contract. Crap. We don't really have assets to trade for him, at least not compared to the Celtics who have a lottery pick.