The NRL is set to sanction Adam Reynolds and Pat Carrigan, with the Brisbane Broncos' superstar duo hit with breach notices after they were filmed in a skirmish on a night out.

Broncos captain Reynolds and vice-captain Carrigan have apologised for their scuffle, which came to light when video footage surfaced on social media.

But while Brisbane decided not to suspend the duo, the league's integrity unit has stepped in and given the pair five business days to respond to accusations of violating the NRL's code of conduct.

"Both players are alleged to have engaged in a physical altercation in public which has brought the game into disrepute," the NRL said in a statement released on Friday afternoon.

"The NRL has reminded other players involved in the incident of their responsibilities under the NRL Code of Conduct."

Fellow players Reece Walsh and Payne Haas were seen in other footage playing a minor role in the scuffle, but are not accused of breaching the code.

Any suspension for Reynolds and Carrigan would rule them out of the Broncos' March 3 season-opening clash with the Sydney Roosters in Las Vegas.

Brisbane face North Queensland on Sunday in Mackay in a trial game, with Reynolds and Carrigan named to start.

Speaking earlier this week, before the breach notices were issued, Brisbane coach Kevin Walters played down the incident.

"We had a blip on Sunday evening. It was in-house too, no one from outside was involved," he said.

"All they've done is really hurt themselves and the brand, more than anyone from the public.

"We won't be suspending them ... it's out of our hands now and into (the NRL's)."