If your camera has aperture priority you could set a large aperture (small number-like f/2.8 or f/3.5-whatever are the smaller numbers that your camera is capable of) so that you can use a decent shutter speed and ISO to prevent as much camera shake and noise as possible.
Just consider that the larger the aperture, the shallower the depth of field. So your focus will have to be spot on or very little will be in focus. But if you have the shutter speed too slow, all the action will be blurred. A little motion blur can look great in a photo like that because it is more dynamic than a frozen action shot. But you don't want it so blurred that you can't tell what the subject of the photo is.
Basically, you want to find the best ballance between shutter speed, aperture and ISO that will allow for the clearest, and sharpest photos possible. You might try to practice shooting at the arena before hand. Snap off shots to see how it works.
If you don't have aperture priority, you have to completely depend on the camera to choose the settings for you using the scene modes to tell the camera what you want the image to look like. For instance, if you want to freeze the action, then use the action mode. If you want to blur the background for more of a portrait look, then use portrait mode. If you want to get a more dynamic action shot, you could try the landscape mode. It will have a wide depth of field but the shutter speed may be just slow enough that you can pan (move the camera to follow the action) to get that dynamic blurred action shot.
Read your manual to get a better idea of the modes on your camera.