I think Bender is an interesting gamble for the Celtics. We can stash him overseas for a couple years and use that roster space for a few of our other picks in this draft. Odds are he's not worth #3 overall but who knows. I'd give him a 5-10% chance of being as good as Kristaps P. on the Knicks.
How would you stash him? Is he under contract still overseas? If not, why would he stay overseas?
Teams can't just decide to "stash" guys.
He is in fact under contract overseas for several more seasons. That said, his buyout isn't very large and he has stated that he wants to come to the US next year. I'd like him more if he were willing to stay overseas for a bit longer, myself. The C's wouldn't have to sign him because he's under contract (at least, I think that's the rule), but it's a bad way to start out a relationship unless he says he'd be willing to during the pre-draft process.
The team is never obligated to sign a player, and they retain their rights for a full year after the draft (which is why the Philly signed Embiid and Noel when they did). If they play any professional games (or are under contract in a professional league-I'm not 100% on that specific part), then that one year starts either after each game or at the end of each overseas contract (this is the part I need to check again)
So as long as they play overseas, the team that drafted them retains the rights. And after a few years, the player is exempt from the rookie scale.
Between teams being able to contribute only $650k to buyouts (Bender's is $1.3 million, so the rest comes from his contract/pocket) and possibly getting more when not subject to the rookie scale, some players (Mirotic, Saric) decide to play overseas and come over later. Others want the guaranteed money now and better development available in the NBA (Porzingis)
Everything Bender has said indicates that he wants to play in the NBA from day 1, but it's always possible that Danny talks to him and he'd consider staying overseas (or that Danny says he'll only draft him of he agrees to play overseas, like Marcus Thornton or Colton Iverson). It'll be interesting to see how it plays out