Why are Coach and Rowdy important to the storyline?

Rowdy is Arnold's best-friend and their friendship becomes one of the novel's biggest challenges. What will happen to their friendship is one of the story's big questions..... will their friendship survive. This is important because we, as readers, become invested in the outcome.

Coach is important because of his optimism and the interest he takes in Arnold. He is a stabilizing force in Arnold's life and provides immeasurable encouragement.