Happ not playing any waiting game, said he's testing the NBA waters but if he doesn't get a 1st round grade, he's coming back. I can't see him being a first round pick, he's not what NBA GMs are infatuated with. That said, I could see him having a long career in the right spot. He could be a good fit in a rotation at the end of the first round on a contender that isn't necessarily looking for the huge upside that he doesn't provide. I don't know what the draft looks like, but I can't see a rebuilding team taking him really at any point.
He also said there's not a chance he seeks a grad transfer. I know those rumors had been floated, not sure how reputably.