Canberra and Cronulla are bracing for the prospect of becoming crash-test dummies for the latest NRL crackdown as Raiders coach Ricky Stuart warned a zero-tolerance approach to head-high contact could lead to games being reduced to 11-a-side.

The Raiders host the Sharks on Thursday in the first game since the NRL sent an edict to clubs, conceding the officiating of head-high shots had slipped with officials now urged to send more players to the sinbin in round five.

Historically such crackdowns have led to an overcorrection from officials with the 2021 Magic Round the most notable example.

The game's renewed tough stance will be of little solace to Sharks coach Craig Fitzgibbon after last week's 20-6 loss to Canterbury.

The NRL admitted in the aftermath of Cronulla's defeat that Bulldogs hooker Reed Mahoney should have been sinbinned for a high shot on Sharks utility Daniel Atkinson.

"It (the Mahoney incident) is almost irrelevant now, you hand it over to the people who make those calls," Fitzgibbon said.

"If they make them, they make them.

"You don't want to be on the (wrong) end of a soft one either now, so we'll wait and see what happens this round."

Those views were echoed by Stuart, who said it was natural for players to make innocent mistakes during the heat of battle.

But Canberra coach Stuart has said referees must be "consistent right throughout the next seven games" after the Raiders-Sharks clash opens round five.

"There are so many high shots that are accidental but if they're all going to be going to the bin, there's going to be a lot of football where we've got 12 v 13, or 12 v 12, or 11 v 11," Stuart said.

"Because there's periods of play where the speed and the intensity of the match creates so many unexpected high shots that are not preempted.

"So it's going to be an interesting round of football if they (the referees) are consistent for the whole eight games, which I hope they are, and I'm sure they will be."