If coaches, teachers, and anyone else wants to pray at school, it should be done at times when they are not actively in charge of kids or in ways that don't involve the kids.
My coach did this pregame, every game, as a pump up(?) or something like this. He waited until the team got in a tight circle, we already had captains do their thing in the circle, then he prayed. I was one of 3-4 non religious kids on the team. It was weird as eff to me and it also very much so was an excluding activity.
I just don't get why that should be a thing at all. Do your thing, just stop doing it at times that are not appropriate. Pray before the team gets there. Pray at home after the game. Pray silently in your head where ever the hell you want. People that don't get this simply don't want to get it.