There has been an expectation that Ponga will make the shift from fullback to five-eighth at some stage of his career in a move akin to that made by Broncos great Darren Lockyer.

Former Knights coach Nathan Brown tried to fast-track the transition by handing him the No.6 jersey at the start of the season.

The experiment lasted three games before it was aborted and Ponga switched back to the custodian role.

O'Brien has yet to officially start at the Knights but the rookie coach has already made his first big call in declaring Ponga will be wearing the No.1 jersey in 2020.

"I won't be experimenting with him in the halves; he will be our fullback," O'Brien said.

Ponga hasn't yet had an opportunity to properly catch up with O'Brien but said he had no issues with the decision.

"I'll play wherever the coach wants me, so if he wants me at the back I'll play at the back," Ponga said.

"I've said it before and I'll keep saying it, I'm easy. Wherever the coach wants me and whatever suits the team. "I've said 'G'day', met him and said 'how you going', but we haven't really spoken.

"The whole club, all the boys, are very excited to start and rip in. We've got a new coach and we're excited to see what he brings and get working."

Ponga will be one of the headline acts when the World Cup 9s kick off at Bankwest Stadium on Friday night. The playmaker has a freakish ability to bamboozle defences in the 13-man version of the game and is expected to come into his own as part of a star-studded Australian outfit during the two-day tournament.

"Obviously taking players off the field and and opening space up, it does cater for players like myself," Ponga said, adding that outside backs like Josh Addo-Carr and Maiko Sivo would thrive.

''Sivo is a hard bloke to stop when [defences] are at full strength. That Fiji side is going to be insane,'' he said.

"There are players who have the speed or have the agility, and then there a players who have speed and strength. There's a lot of talent and a lot of skills that will be displayed and that's the beauty of nines. It's game after game of action, so from a supporters' view, it's pretty cool."

The nines provides Ponga an opportunity to finish a rollercoaster season on a high. The Knights missed out on the finals despite enjoying a six-game mid-season winning streak, ultimately resulting in Brown parting company with the club. Ponga showed glimpses of brilliance that have him pegged as the most exciting talent in the game but will be hoping to produce them more consistently under O'Brien - not that he was prepared to reflect on the season just gone.

"That's behind me," Ponga said. "This is a different jersey so it will obviously have it's own story. I will put that behind me and look forward to enjoying myself this Friday and Saturday."