If he leaves, he needs to get ready for European style of play. The kid is not ready for NBA.
Odds on making a roster on 30 NBA teams.
Avg of 14 players on each team
448 players
0.09% chance of making a team
On 2017-18 opening day NBA rosters, former NCAA players filled 83% of roster spots (all from Division I schools).
NCAA student-athletes played internationally, in the NBA D-League, or in the NBA as undrafted players (535 from Division I, 181 from Division II and 35 from Division III) after leaving college; this includes international players who attended NCAA institutions. These numbers were combined with the NBA draftees to calculate an approximate NCAA to Total Professional opportunities figure (calculated as [50 + 751] / 4,158 = 19%).
http://www.ncaa.org/about/resources/research/estimated-probability-competing-professional-athletics