Basketball is a major part of Junior's life in The Absolutely True Diary of a Part-Time Indian. Though born with multiple medical problems, such as excess fluid in the brain and eyesight problems, Junior strives to join the Reardan team and prove himself despite everyone's expectations.

During the tryouts, he has to push himself: the coach has the potential players run multiple laps, causing a few to give up from exhaustion. During the next phase, the coach has the students play against one another one-on-one, pairing Junior with the much taller Roger. Roger dunks often and takes the ball from Junior multiple times. The coach asks Junior if he wants to give up, but Junior is steadfast and refuses. This resilience endears him to the coach, as does his subsequent improvement during the tryouts—he fouls Roger. Junior makes the team.

Next week, the Reardan team plays against Wellpinit's. Still believing Junior to be a traitor for choosing an all-white school over the reservation's school, the Wellpinit spectators harass Junior. Only Junior's estranged friend Rowdy does not heckle him. In the first quarter, Junior gets hit by a projectile thrown by one of the Wellpinit spectators, causing him to bleed and have to leave the court to get the injury stitched. However, he refuses to give up the game and returns. The game ends for Junior when Rowdy knocks him unconscious. Reardan loses.

Reardan wins twelve consecutive games after this loss, with Junior becoming one of the best shooters on the team. They face off against Wellpinit again, with Junior determined to prove himself to everyone. Junior performs well and helps secure victory for Reardan, but the win is tainted when he realizes how far the scales are tipped in Reardan's favor. Not all of the kids on the Wellpinit team even have enough money for breakfast. In particular, he thinks about how his friend Rowdy will be beaten by his father for losing the game. However, after sending Rowdy an email apologizing, the two reconnect and rekindle their old friendship.