Workouts. I think he's smart to keep his options open...
There are a lot of reasons to leave school early---gives you the opportunity to train and treat bball as a full time job to develop, better competition, $, coaching, etc.
There are legitimate reasons to come back---that doesn't mean there aren't legitimate decisions to leave early to be a 2nd rounder.
I've talked to a few people about his prospects and some have said they think he will likely get drafted and make a team.
I'm also one who thinks euro ball is vastly underutilized for college players. If I were good enough to play professionally I would play professionally at a place that has a track record of solid development and drop out of school.
I think it's ridiculous people think that a player is dumb for going pro early--or for coming back to school. There are good reasons to do both and most on CB are too shortsighted to see the full picture and set of options.