If lunch was lightUse an easy carb plus a little proteinKeep fat and fiber moderate so the snack digests before practice starts.
If the bus was lateGo smaller and faster-digesting, not emptySkip heavy fat or fiber this close to practice; it will not clear in time.
If practice runs longPack a second snack for the back halfPack crackers, a granola bar, or fruit snacks with the water bottle.
The pre-practice snack is not extra credit. It is the difference between training on empty and training well.