Lion,
With all due respect.....asking him to pull himself out after first inning was not the best choice. You should have made it CLEAR to him that if the coach actually was ignorant enough to plan a start for him, he should have never agreed. The pregame warm ups with the previous work load was NOT good. Heating up a pitcher with that work load is asking for trouble....pitchers throw at max effort prior to entering a game, and was not prudent.
Prayers, and best wishes for his shoulder. Shame on his coach....and in retrospect I would guess you would have given more clear, and safer guidance.
Best wishes!