highwinds,
Sorry to see your son in this posistion.
Lots of good advice so far but I want to emphize one point. Do not let him quit before this season is over. After the season all bets are off.
Short story.
A friend and summer teammate of son, a jr. in HS quite his HS team mid season because he felt he was not getting the playing time he deserved. He is a good kid and a good player but unfortunatly this summer he will have to put up with the inevitable whispers that he quit on his high school team. I must admitt that I will view him through different colored glasses.