Especially if it's a really competitive Varsity team, it is to your son's benefit to be able to play multiple positions and "hit" himself into the lineup. RipkenFan Son started 6 positions in HS (all but 1b, P & C). In both HS and Legion to an extent, he played with a number of players who were not as versatile. I used to kid him about what it was like to be the "fastest thirdbaseman" in the state when he was put there. Varsity coaches will often play seniors more, though insert underclassmen where there are spots to fill. Son used to bring both Infield and Outfield mitts to college showcases.
Son often said that his mindset was that of a MI, though he could play outfield. The college where he landed told him they recruited him as an "athletic infielder who could play OF." In college he played 2B & SS primarily., some CF in scrimmages.
Now last year he played 2B, SS, 3B, CF and LF with a team that values versatility.
To summarize, stay versatile, keep your hitting solid, and enjoy the game!