It's about time for mid-season minor-league promotions. My guess is Rosario is headed for AAA, but because he's already on the 40-man, it costs nothing of importance to bring him to the big club as a detour, and let him pitch a few innings to give the beleaguered bullpen some rest. If he happens to pitch lights-out, sure, he'll stay up, but likely he'll depart after a few games and head toward Rochester instead of Chattanooga.