Why does my coach do this to me?

Ok, so I'm a junior this year at a very small high school and I'm on the varsity soccer team. I'm a lot better than most of the girls on the team, and my coach even puts in girls that aren't as good as me out on the feild while I sit on the bench the whole game. My coach says that it's because they need more players for the jv games, but then why did he not just put me on the jv team if he always has me play down?