It's gonna be tough with typical lousy high school lighting. Scott's suggestion for using a flash is worth trying.
If you are feeling ambitious and creative, then consider crafting a rig to have the flash below your camera spreading light low and out. I've seen some clever setups with tripod clamps, c-clamps, and plastic pipe attached to a monopod that holds the camera. If you have a flash bracket it may help.
You can use a relatively unsophisticated flash. You'll need an off-camera flash cord that has a hot shoe extension with a tripod mounting hole.
And of course you'll be limited in the rapidity of shots. You'll probably get one good opportunity per play. Good for developing discipline
Not that many people have this stuff hanging around on a day's notice, but just in case you do, make the most of it.
M