New Zealand Rugby has launched a new initiative to stop players from returning to the game after suffering concussion.
It's called the blue card, and is set to be rolled out to 14 provincial unions.
The blue card can be issued when a referee suspects a player has suffered a concussion. It means they must immediately stand down for at least three weeks, and obtain medical clearance to return to play.
New Zealand Rugby head of community rugby Brent Anderson says there's a shift in how players view going back on the field after concussions.
"I think there's been a quantum shift… Previously if a player took a knock and got back into position to play, people would applaud on the sideline. Now they're saying it's time to come off, so the players are taking that on board."
He says it's erring on the side of caution but it's for player welfare and players see the need for it.
The idea was successfully trialled in Northland, and will now be rolled out to the 14 largest unions.
Mr Anderson told The AM Show in Northland they saw a potential concussion about one time in 19 matches.
Former All Blacks doctor John Mayhew says it's a necessary and good innovation. He says it's especially important for lower-level club rugby.
"It can be a jungle out there and certainly the group I find hardest to deal with is that 15 to 20-year-old age group… It's their most important part of their life and their career - convincing them and their parents head injuries are important - it can be difficult."
He told The AM Show he doesn't think it will change the game.
"Just because it's going to be difficult to do, doesn't mean we shouldn't do it."
Every year more than 7000 Kiwis suffer head injuries in sport, with rugby the most common.