Asst. Coach

I help coach a 10u travel team. It is my daughter's first year. The head coach had told all of the parents that he was going to bring in another player to help pitch because we only have one pitcher, who happens to be his daughter. When the tournament began, he pitched her like he said he would. When the elimination games started, he played this girl in the field over girls who were there all season. Many of the parents were obviously upset including myself. His reasoning was that teams do this all the time. I guess I'm wondering if this is acceptable, even at such a young age?