I am going to say this out loud in an attempt to get some explanation. I don't understand parents?
My suggestion is get a rule book and educate yourself.
The DH in HS, college is not the same as the DH in proball and was he used as the DH or as an EH?
How are we supposed to know why your son's coach used him that way? Get used to it, your son can be used at anytime in anyway any coach wants especially in the beginning when he is trying to figure out who goes where and when, he's learning too.
If you came here to learn, why would you claim that you came here to nit pick the coaches decisions? Unless the coach puts your son in harms way, it's yor duty to support his decisions for the TEAM, not just your son. If you wish your son to play after college, get used to that concept, there is no i int TEAM!