This unnamed man is the coach of the Funky Dunkers. He appears in Big Shot.
He helped the point guard when Preet stomped on his foot with his boot then when Susan Heffley told the head ref that she wanted to win fair and square, the coach agreed and said he'll take Preet then he is shown to be carrying Greg when he made the final shot and won for his team. At the end of the book he took the team to get ice cream.