North Queensland coach Paul Green wants the NRL to crack down on clubs trying to induce players to make early transfers before their contracts are up.
Green remains steadfast that the Cowboys won't agree to an early release for youngster Kalyn Ponga to join Newcastle before the beginning of his 2018 deal, despite continued pressure to let him go.
Instead, the 2015 premiership-winning coach believes any suggestion Ponga should be released is unfair.
"We're under enormous pressure from different people to release Kalyn Ponga and there was no reason why we should," Green told TAB Radio on Tuesday.
"We held our end of the bargain, he'd signed for another year so that was our attitude all the way through."