I wouldn't stress over it 2016. When I made Varsity as a Soph. I was a catcher but I eventually became our DH 3 games into the year. Tell your son to stay upbeat about it, tell him to look for tendencies and tipping pitches. As a DH I didn't have to worry about fielding all I did was study the pitcher, take some air cuts off the tee while the team was in the field and I was ready to go. Don't sit on the bench and shoot the stuff with the bench guys. Always be mentally ready. I DHed my entire Soph. year eventually landed in the 4 hole, and Jr. year I split time with a Sr. at 1B, I played 1B when he pitched. Being a DH can help you develop as a force at the plate. Just have the right mindset and still during practice work on the glove.
great attitude right here!