USA Wrestling has expanded the medical coverage on their cards to include all wrestling events, whether sanctioned or not. However, the same is not true of the liability insurance protection. If you have an unregistered wrestler or coach participating at practice and an accident should occur, USA Wrestling would provide no liability protection for the members or the clubs involved.
If an unregistered wrestler goes to a tournament, and an injury occurs at the tournament, the liability coverage provided by the event sanction is likewise void (this would be true even if the unregistered wrestler was not involved in the accident). Do yourself and everyone else a favor, and see that all the coaches and wrestlers in your club have current registrations!