Later he throws the meal up in the bathroom. He is weak and dehydrated during the game. The coach can't figure out why. The above menu looks like a good pre-event meal. It's high in carbohydrates, has some protein and provides plenty of fluids.
Some athletes have a nervous stomach and find it hard to eat anything before competing.
Others get a queasy stomach around big games and tournament time. If they eat they may throw up before the game. If they don't eat they feel weak and lack energy. It will be out of the stomach within 1-2 hours. The athlete is left with an empty stomach but fueled muscles.