The NRL says it is comfortable with its rules regarding the shoulder charge amid growing calls for the intimidatory tactic to be banned. A simmering issue since Frank Pritchard\'s knockout blow on Penrith winger David Simmons in the opening round of the season, the shoulder charge was again in the spotlight with Brisbane back-rower Ben Te\'o flooring Wests Tigers prop Matt Groat on Friday night. Te\'o was placed on report for the tackle. A concussed Groat took no further part in the game and is considered an unlikely starter in next week\'s game against Penrith. Former longtime Canterbury and Australian doctor Hugh Hazard called on the league to ban the tackle - as it is in rugby. But NRL director of football operations Nathan McGuirk claimed existing deterrents were strong enough. \"We made some pretty important changes to our rules five years ago ... where if a player is deemed to have made at least careless contact with his shoulder to the head of an opponents, then there\'s the possibility they may face further action from the league,\" McGuirk told ABC radio on Sunday. \"We\'re quite comfortable with the changes to the rules that we made.\" He said if clubs or the rugby league players\' association \"come to us and want to review our current policy on the issue, then we\'re happy to have that conversation\". The incident involving Te\'o opened up another can of worms, with Groat\'s concussion leaving the Tigers down a player for more than half of the contest. New rules brought in at the start of the year mean any player determined by the club doctor to have suffered a concussion is not permitted to return to the game. Tigers coach Tim Sheens suggested teams should have the option of bringing in an 18th man in such cases, especially where the concussion is deemed to be a result of foul play. McGuirk said the option had been canvassed by the rules committee prior to the season, but admitted it would likely come up for discussion again. \"We\'ll probably talk to our clubs and the competition committee and see potentially how something like that could work. But there are a lot of ramifications around how that change could impact the game.\"