NRL Head of Football, Todd Greenberg.

NRL Head of Football Todd Greenberg has said he is prepared to look at both an 18th man replacement and into recent concerns around players 'diving' over the coming months.

While the recent concussion guideline amendments around whether a player should return to the field or not remain in effect, Greenberg referred to the 18th man replacement as a possibility in interchange adjustments moving forward.

Speaking after a meeting with the majority of NRL coaches, Greenberg said all of this would be taken into consideration though it will take time for anything to be confirmed.

"One of the possibilities we considered was whether we could have a substitute player for foul play and that's certainly already in the review and has received a lot of discussion from the coaches," Greenberg said. 

"It's not so much important because of concussion, rather it's important if we decide to go down the path of lowering numbers of interchange.

"We articulated a strong timeline where we'd be looking towards early July for confirmation. It's a big decision for the game so we need to make sure we have enough information to make a decision."

Greenberg also touched on the latest talking point in rugby league, that being diving. 

With controversy over the weekend involving some penalties that may have been milked by players across several games, Greenberg confirmed the coaches talked about diving. But he noted such things go hand-in-hand with the general "use of technology in the game" and when technology should and shouldn't be used.

"There will be no change under the current model but it is something I agreed with the coaches to look at to see if there is an opportunity to review our current practices," Greenberg said.

"The thing we talked about today is the threshold, that's the word I've used to the coaches. For a video referee to review whether something is on report or not, the question is whether that threshold is too low and perhaps they should only come in on a much higher threshold, which would stop the diving.

"What it is there for is that we don't miss things, and again that comes down to same critical issue of accuracy versus efficiency. We want to make every decision the right one but clearly we want continuous play so there's a balance."