0 walks in the past 10 games? He's on fire, and hitting very well. But that walk rate HAS to improve. He's not going to hit .350 at the big league level, so he's got to be able to get on base other ways.
Even if he hits .300, his OBP will only be around .320. Those are Cristian Guzman type numbers.
There's still time, but its starting to get worrisome. Especially since he's Dominican, and they dont have the greatest history of taking pitches.