The NRL is considering ramping up its concussion protocols further with saliva and blood testing after introducing a mandatory 11-day stand down for players after brain injuries.

The ARL Commission confirmed the most significant changes to its concussion policy in almost a decade on Wednesday, declaring player safety is the game's No.1 priority.

Under the new rules, which come into effect from Thursday, players who have been diagnosed with a concussion will be automatically stood down from contact training or playing for an 11-day period.

That will mean they are guaranteed to miss the following weekend's match, and potentially a second game depending on turnaround times.

Players will only be able to return sooner in exceptional circumstances, and after approval from an NRL-appointed independent neurologist.

To return early, the player must be asymptomatic the day following the concussion and cognitive testing must have returned to normal.

Players will be ineligible to apply for an early return if they have had five or more concussions previously, experienced a concussion in the past three months or have already gone through a prolonged recovery.

Exemptions will not be available to any player deemed to have received a category-one concussion in a match or in training - determined by a player losing consciousness, failing to protect themself while falling, or showing unsteadiness on their feet after a head knock.

The rule change comes as injured players launch a class action against the AFL, seeking up to $1 billion in damages.

The NRL say their changes are about player safety rather than legal threats, following advice from experts and after watching worldwide trends.

"That (class action) is not a matter that is within our control," NRL chief Andrew Abdo said.

"What is in our control are our policies and procedures and making sure we can do everything we can to create a safe environment.

"We are constantly reviewing that.

"This is purely based on what we know listening to our experts and what we know is right for our sport."

Abdo insisted the ability for players to potentially return earlier was important, and backed the 11-day timeline.

"There is no exact science that points to how long it takes a player to recover from a concussion," he said.

"It is all case-by-case and very individual. Our policy needs to take that into account.

"We don't want players not reporting concussions for fear of a mild concussion ruling them out for a period that is longer than necessary."

The NRL confirmed it would consider monitoring technologies such as blood and saliva testing as a tool for diagnosing concussions.

Two years ago, British researchers reported a study of 150 rugby players between 2017 and 2019 had shown 94 per cent accuracy in picking up concussions via saliva testing.

The US Food and Drug Administration last week approved a commercial blood test to assess concussions, with results available within 18 minutes.

The 11-day stand down marks the biggest change to the NRL's approach to concussions since the introduction of the head injury assessment system in 2014.

The protocols have the support of the players' union, and bring the sport into line with World Rugby, which last year introduced an 11-day stand-down period for the 15-player game.

The changes come days after the latest concussion suffered by Kalyn Ponga, with Newcastle weighing up how best to deal with his fourth brain injury in 10 months.