SOUTH Sydney coach Michael Maguire has thrown cautious support behind the introduction of an 18th player amid fears it could be open to exploitation.
The NRL competition committee will on Wednesday debate the addition of an extra man on to every reserves bench which could be used in case of concussion or foul play.
"It's something that the game definitely needs to look at," Maguire said.
"They've really probably got to make sure they test it because there's so many areas that can be scrutinised with the 18th man. I'm sure we'll nut that out."
Maguire and Sydney Roosters counterpart Trent Robinson sit on the committee along with Australian captain Cameron Smith and NRL CEO Todd Greenberg.
The issue has been gaining traction with some coaches over the past month since Newcastle coach Nathan Brown led the calls after his side lost two players to head knocks in their close loss to the Rabbitohs.
Brisbane coach Wayne Bennett has resisted the notion, saying it was a slippery slope and predicted it would lead to calls for a 19th man.
The NRL is attempting a difficult balancing act over concussion rules.
Under NRL rules, when a player is taken off for a head injury assessment, it does not count towards the side's interchange limit.
Parramatta were last month forced to defend themselves against suggestions they were using the concussion rules as a loophole for a free interchange.
They were issued a please explain by the NRL after captain Tim Mannah was sent for a head injury assessment after receiving a poke in the eye, only to return to the field later in the game.
Maguire admitted he feared an 18th man could likewise be exploited and when asked if the rules were open to being stretched, he said: "That always opens up the opportunities doesn't it.
"How they use that 18th man, that's something they need to be thorough with, be sure of the rulings."
Update your news preferences and get the latest news delivered to your inbox.