Cincinnati in September, assuming he continues to dominate AA as he has so far. Anything more than a 1.50 ERA in AA keeps him in the minors until next All Star break.
Say what you will about Bailey's offspeed pitches, his work ethic, or the propensity of high schoolers to break down, he's been an outstanding prospect this season. He's among the top handful of pitchers capable of ace level status and his ceiling is growing ever higher.
The promotion, in short, has worked wonders, despite what many of the so-called experts on this board prophesized.