The NRL is so serious about stamping out the scourge of trainers spending too much time on the field it has flagged the possibility of deregistration in the most extreme cases before its new season crackdown.

On the same day head office confirmed it had set up an appointments panel to take away any allegations of nepotism in referee allocations, the game is readying a raft of sanctions for loitering trainers.

Cautions, fines and even deregistration - in the case of serious serial offenders - have all been tabled by the NRL as they attempt to ban scores of trainers relentlessly running messages during games.

Blue shirt trainers will be required to provide a card to interchange officials every time they enter the field for tactical purposes, limited to three per half.