In shooting most indoor sports especially basketball, the white balance on one end of the court will be entirely different than on the other end. Most school venues have entrances that are lead to the court, some of course have skylights above goals or nets.
One thing that might assist you is the Expo Disc
Also the Color right white balance tool and a couple of their offerings are sold on Amazon
My solution was to set one body color balanced on one end of the court, and one color balanced at the other end of the court when white balance became a constant issue.
One solution depending on where you are allowed to shoot, your positon, the stands or along the lines is to position your self, set the color balance,
You want to shoot with the action coming toward you no matter what the color balance, you want to capture the players faces, not their numbers moving away from your position on the court
Expodiscs come sized, if you have a long lens be sure and purchase the Expo Disc for that sice lens, and then you have the option of using it on smaller diameter lenses