Looking at his record at El Paso this year. He hit .314 -- so he must have some idea of what he's doing at the plate. A career .331 hitter in the minors, does he really need THAT much more seasoning?
Not to mention his 130+ ABs at the ML level, and however more he racks up before the season ends.
He's also REALLY fast. Lastly, looks to me like he could maybe put on another 5-10 pounds of muscle without losing quickness.