NRL chief executive Todd Greenberg says the organisation is doing all it can to manage and prevent concussion with the looming threat of legal action by former players.
Two law firms are reportedly set to launch a class-action suit against the NRL after investigating the issue of concussion in NRL players for the past 12 months.
The investigation revolves around the degenerative brain condition Chronic Traumatic Encephalopathy (CTE), which has been found in retired American NFL players and last week revealed to be in the brains of two former professional rugby league players.
Asked if the NRL's policies and procedure would stand up to a legal challenge, Greenberg said the organisation had made great strides in the area and followed the most recent guidelines of the international Concussion in Sport Group (CISG) consensus statement.
"The policies and procedures we have put in place around concussion and our return-to-play guidelines are world's best practice and they come out of the consensus on concussion which is an international global best practice," Greenberg said on Monday.
"We have made huge changes going back to 2014 and I'm very confident those rules are in place for the primary reason for the care of our players.
"But as science evolves we will continue to tighten those policies but I'm very comfortable with the level of care and importantly the level of assistance we provide to our trainers and doctors."
The NRL has been urged to make public its research on concussion but Greenberg said it was too early to do so.
He couldn't quote an exact monetary figure that the NRL had spent on such research but said it was an "enormous amount of money, resources and investment of time and energy" over the past few years.
"We are listening and learning a hell of a lot - we are talking to experts both here and abroad trying to understand how this science evolves," he said.
"We have to continue to evolve it and have the very best people overseeing our players, clubs and working with our doctors to make sure we are doing everything possible in what is a contact sport."
Greenberg said it was pleasing to see a cultural shift surrounding concussion, when playing on after a head knock was no longer a badge of honour.
"This part of our game has changed enormously over the last few years and I'm very proud of the people inside the game for embracing that change," he said.
