The 40 man roster has nothing to do with minor league assignments. Cody Scarpetta is on the 40 man and pitched for WI last season and is pitching for BC this season, A and A+ respectively. Simply put because real prospects don't spend much in AAA at all anymore, so many people think the pitching in AA is actually better than AAA. The true prospect pitchers are in AA, the guys that throw gas, locate it, and have plus secondary stuff, As BK noted AAA has become more of a storage area for fringe MLB talent, AAA isn't about development anymore. Mike is only 20 years old, he was far and away the best hitter in the Southern League, and the Marlins could use his bat. If he succeeds everyone is happy, if he struggles a bit he gets dropped back to AAA. He's just been that good that he's getting the call straight from AA, I don't think anything more needs to be said.