According to Bleacher Report, he would be #13 to Phoenix. I think it's hard to tell a kid to come back to school if he is going to be picked up in the lottery.
http://bleacherreport.com/articles/2416246-2015-nba-mock-draft-updated-first-round-projections-going-into-ncaa-final-four/page/14
http://bleacherreport.com/articles/2416246-2015-nba-mock-draft-updated-first-round-projections-going-into-ncaa-final-four/page/14