Hoop Rat

"Trey, the Spartans' team captain, becomes fast friends with Griffin, the newest member of their squad. The problem is, Griff used to play for the Spartans' biggest rivals, the Goliaths, and the rest of the Spartans think he's a rat. Trey doesn't know what to do. His teammates want him to betray his friendship with Griff to save their season-- but if they're wrong about Griff, then Trey will end up being the rat"--Unedited summary from book.