He might only have fond memories of Johnathan Thurston but that could all change for Cronulla coach Shane Flanagan after Saturday night’s NRL knockout semi-final against North Queensland in Townsville.

Flanagan’s face lit up at the mention of Thurston’s name on Friday before revealing he was the 2002 Australian Schoolboys’ mentor of the dangerous Cowboys’ playmaker.

He helped Thurston become a big-game match winner – a fact that might come back to bite him this weekend.

“I’ve had the pleasure of coaching him when he was a young kid,” Flanagan said.

The Cronulla coach might share special inside knowledge of Thurston but admitted he was no closer to finding a way of stopping him.

“What really impresses me about JT is it’s just effort on effort on effort – it never stops,” he said.

“He’s on one side of the field, then he’s on the other side of the field.

“It’s not like some of these halves these days that stick to one side.

“He’ll pop up on kick-chase – he’ll pop up everywhere.

“We need to be on our game and treat him as we treat all the other players but add a little bit more attention.”

Thurston will hope to spark a Cowboys outfit that wants to keep alive their maiden title hopes in their 20th year.

That might be easier said than done against a Sharks side also looking to end their own 49-season title wait.

North Queensland have conceded the first points and the first try in seven straight games.

A resurgent Sharks – the 2014 wooden spooners – have scored the first points in nine of their past 10 games.

The Cowboys have also jagged just one win in six games against top-eight opposition of late.

Cronulla have won six of seven.

The winner faces the Storm in Melbourne in next week’s grand final qualifier.