NRL must address concussion: Brown

Almost a year to the day after concussion rules were tightened, Newcastle coach Nathan Brown says NRL rivals are making a mockery of it and that his club is being punished for following it.

Brown has also renewed calls for an 18th and possible 19th man to be introduced to cover the loss of concussed players after being reduced to 14 fit men in Saturday night's 53-0 loss in Brisbane.

At one stage debutant Josh King was the only man left on the Knights bench after the visitors lost Jarrod Mullen, winger Nathan Ross and hooker Tyler Randell to concussion.

Last April the Australian Rugby League Commission stiffened concussion rules, ensuring any player showing symptoms stay off the field for the rest of the game.

Brown said they were following the rule - but claimed others were bending it to their advantage.

"I don't think I am the only coach sitting here saying it," Brown said.

"We've got to look at it.

"We are one club who is following it to the letter and for that all we are getting is punished.

"Because there are people out there who are bending it.

"You watch some players who come back on, or stay on and are shielded.

"Then there's the other case where guys are deliberately lying down and using a head knock to get a free interchange.

"There's a mockery being made of it at the minute."

It was already a subject close to Brown's heart after Newcastle winger James McManus announced in February he would sit out the 2016 season due to concussion.

The former NSW flyer has not taken the field since round 20 2015, when he copped his second head knock of the season and collapsed near the sidelines against South Sydney.

It hit home again after Mullen, Ross and Randell were forced off the field in the Brisbane romp.

"The NRL has to address this concussion rule," he said.

"If we are going to go down this path we need to have more players.

"We should have an 18th and 19th man.

"We go to the letter by ruling people out but we are getting punished, forced to leave young kids out on the field and it's unfair for their development.

"In the end it wasn't a good spectacle (against Brisbane).

"I don't think we are going the right way about it at the moment."

Brown was unsure whether his concussed trio would be cleared to play for their next clash against Manly on April 25.

"With a nine day turnaround you'd hope they'd be okay but I can't say," he said.