I'm no Arizona prospect expert, but I've heard his OF defense was less than adequate, so I would expect him to primarily be a 1B now.
Just looking at his numbers, I would think that over time a lot of those doubles will turn into HRs, especially in Arizona. 38 doubles at this point in the season is very impressive. You also have to be impressed by his amazing plate discipline. 69 BBs and only 32 Ks is rather remarkable. I personally believe that if his power increases as I expect it to, he could be one of the better offensive 1B in the league someday. Hard to argue against him having that kind of potential anyways.