Switch the metering mode to spot, set the camera to manual, pick a shutter speed that is fast enough to freeze the motion you expect, then meter someone's shirt as they stand just a little bit away from you. Make a note of what it tells you about the aperture you need. If you can't get a good aperture from metering like that, then adjust your shutter speed or ISO until you can.
Spot metering limits the area of the view that gets measured for light, using only the very center of the frame.
Leave those settings on the camera and shoot that way.
If you'd still prefer auto-exposure, choose shutter-priority instead of full auto, and set exposure compensation to +2, as suggested above. Switch back to matrix metering because you won't be able to control what's in the spot if you stay in spot metering. (You might get a player, or you might get background, resulting in very different exposures. Going back to matrix, then compensating, puts the meter back to reading the entire frame.) If that's too much, bump it down a bit. You background will be blown out white, but the court area should be OK.
I don't think flash is going to work for you because you won't really know the distance you're shooting all the time, or maybe you don't want to be restricted to the distance appropriate for your flash. Also, you may get into recycle times and end up missing shots.