Sometimes it's a great idea to simply return to the prayer that Jesus taught us. We can pray the Our Father with our team before or after practices and games. Because it's a well known prayer, we can also ask parents and anyone else gathered to pray with us as we begin our activity.
Our Father, Who art in Heaven, hallowed be Thy name; Thy Kingdom come, Thy will be done on earth as it is in Heaven. Give us this day our daily bread; and forgive us our trespasses as we forgive those who trespass against us; and lead us not into temptation, but deliver us from evil. Amen.