As already stated his foot speed, quickness, and arm strength will determine if he can play in the OF at the next level. If he is to be a first baseman then generally a good stick with some pop is needed. Even though it's not thought of as important but good defense for the position helps. If he is LH then he has more range to his glove side (2nd base hole) but overall if he can cover the hole and the line and handle bunt coverages then he is fine on defense. But again he is at a position where offense is expected over there when playing first.