Fall River Dreams
End of Book
This book doesn't really have a specific antagonist. I think it is partly do to the fact that it doesn't have an individual as a protagonist. It's just the town and team in general. The antagonists would just have to be the different towns and schools competing against Fall River (B.M.C. Durfee High)
All these towns look up to the Durfee program. I would compare it to the Madrid football program. All the surrounding towns want to achieve what they have achieved or even beyond that. The antagonists are very important to the plot of the story. Without them Durfee wouldn't be what it is. No matter how "good" you are, you'll be nothing without someone to play against.