According to David Pick, who's a generally reliable source for Euro rumors:
David Pick @IAmDPick
Source: Brad Wanamaker has put all Euroleague offers on hold with hopes of scoring an NBA deal with the Pelicans or Celtics.
12:29 PM · Jun 27, 2017
Wanamaker is a Pitt alum who has played in Europe post-college. This is interesting in part because he was Zizic's teammate in Turkey, meaning the Celtics probably saw a lot of his games this year. It also brings into question whether a trade involving a non-IT PG is on the near horizon, since such a trade is probably necessary to clear room for Hayward.