According to Real GM, Antetokounmpo is deciding between joining the Knicks' D-League team is Westchester or a deal to remain in Italy/Spain.
Thanasis Antetokounmpo, New York's pick, deciding between D-League Westchester or Spain/Italy deal, sources tell RealGM. Knicks roster full.Acy's contract becomes guaranteed on August 15, and unless the team decides not to keep him on the roster then Antetokounmpo will not be a part of the 2014-15 squad.
— Shams Charania (@ShamsCharania) August 7, 2014
In order for New York to keep his rights, they must extend him a required tender by September 6.
Pro Basketball Talk laid out the team's options in regards to the future of their second-round pick:
I don’t know what promises Antetokounmpo made (many second rounders agree to play in the D-League or overseas before the draft, which increases the likelihood of being selected) or what New York can do for him (many teams in this position help their draft pick find work in exchange for him declining the required tender). But if nothing is on the table for him, Antetokounmpo should consider accepting the tender.
That would likely lead to him joining the team for training camp and, unless the Knicks make another move that trims the roster, getting waived before the regular season begins so they can reach the roster limit of 15 players.
Antetokounmpo would then become an unrestricted free agent. Considering he sipped to No. 51 in the draft, no NBA team would likely be beating down his door immediately. But if he excels in the D-League or overseas, he could negotiate with any NBA team rather than just the Knicks, an advantageous position.