Rugby league great Brad Fittler is advising Paul Green to re-sign with North Queensland and prove himself a genuine NRL super coach, without champion playmaker Johnathan Thurston.

After months of contract negotiations, Green will reportedly put pen to paper in a retention that will make the 2015 premiership-winning mentor the longest-serving coach in the Cowboys’ 23-year history.

The expected re-signing can’t come quick enough for Fittler, who is intrigued to see how Green will fare after Thurston’s retirement at the end of 2018.

At 34, the four-times Dally M Medallist has been accused of playing one season too many after struggling since his return to the game from shoulder surgery.

North Queensland have lost five straight games and, with Thurston and halves partner Michael Morgan yet to reconnect, look a shadow of the side that made two grand finals and a preliminary final in the past three years.

“The salary cap is doing funny things up there and, all off a sudden, there’s a whole heap of pressure at the club that most probably wouldn’t have been there,” Fittler said on The Sunday Footy Show on the Nine Network.

“If I had have been Paul Green, I would have signed a while ago.

“The club and himself have been a really good fit lately and the big challenge for him, I think, is to do it without Johnathan Thurston.

“He’s proved he’s been able to get the best out of a great player and then that has transferred onto other players and a club’s just grown.

“His next challenge is to do it without the champion.”

With Green tipped to commit for another two seasons, at least, the 45-year-old will surpass the late Graeme Murray as the Cowboys’ longest-serving coach, having taken over from Neil Henry in 2014.