My son is a LHP going into his JR year (College). He has pitched all year long since he was 15 yo. Never had an injury. I would be more concerned about conditioning and proper training.
I have been around pitchers at all levels for 13 years or so and most of the pitchers I know play all year. We took a couple weeks off at Xmas time and went right back at it. I have'nt seen one pitcher that is serious about college /pro side lined by arm injury to the point their career was over.
Not throwing enough is a much bigger concern if you are serious. We always played 100+ from 16yo . Spring/summer/fall and then indoors in a giant s****r dome.
Approaching a coach is a bad plan. If he gets the impression that you are a PAIN he will move on. A scout once warned us that if you take time off someone will take your spot. If you or your son are not willing to follow his approach he will pass you by. There are tons who will.
This doesn't mean you let the coach abuse your son but at this point you and most don't know what that means.
At least you are trying to figure that out.
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