Polanco should play at SS until he develops enough to prove he cannot play it in the majors (see: Cuddyer, Plouffe & Dozier,) because he will make the majors with his bat. And if anyone should be promoted because of his bat, it should be Polanco (.340/.444/.453) and not Michael (.327/.351/.404; both slash lines this season.) You just do not move a top prospect (who is on the 40 man roster) from a position of need because there are fielding issues in high A ball. That's what the minors are for, to learn a position and make errors. Last season he played about half of his games in SS. Give him 2 full seasons at SS and then we can talk. He is 20 years old, btw. Plenty of time to improve...