Why does Coach run with Patina during track practice in Chapter 4?

Coach runs with Patina during track practice. At first, as they run he hands her a baton and has her hand it back to him. Then he talks to her about teamwork. He was not pleased with how she acted when she got second place on Saturday, and he wants to remind her that they are a team and she has to stay engaged even is she is not pleased with her performance.