Hi Dean,
I am not sure if you're looking for a general answer. If you have a specific problem, there is a lot more information that is required about the sport and the associations policies. Based on the limited information, it seems that your inquiry is going to involve issues concerning whether the injury is considered an "obvious risk" and if the defences of volenti, inherent risks or dangerous recreational activity applies.
For a general description of liability:
A sports organization owes a duty of care as an occupier to its athletes to reasonably protect them from harm.
You would then have to prove that they breached that duty of care depending on the circumstances of the situation such as the type of game being played, whether the referee was doing their job properly, if the school/association had adequate safety processes, etc. You basically need to show that they were negligent in causing the accident.
Since this is a sports related matter, there is also the possibility that the school or association may rely on voluntary assumptions of risk or dangerous recreational activity defences so that also depends on the nature of the sport. (for example, Oztag is not considered a dangerous recreational activity.)
I won't go into damages because there isn't anything in your inquiry that can really help to give you a better clarification of that legal aspect.
But hopefully it's a start. I am sure that the lawyers in this forum (especially the ones in NSW) can provide better clarity if you have specific questions about the situation.
Good question though
