Newcastle Knights and Queensland Maroons star fullback is all but assured of moving to five-eighth for the 2023 campaign, with coach Adam O'Brien revealing he has been training there during the pre-season.

The revelation from the under fire coach, who may need a strong start to 2023 in an attempt to save his job after a dismal 2022, comes as the Knights continue to reportedly chase Lachlan Miller.

The former Rugby Sevens star made the switch to the 13-man code in 2022 with the Cronulla Sharks, but struggled to find consistent game time in Craig Fitzgibbon's set-up.

When he did play - either at fullback or on the wing - he was among Cronulla's best performers.

According to The Sydney Morning Herald, and as first reported by Zero Tackle back in November, the Knights are closing on Miller and want him to make the switch north.

It's understood that a big part of the Knights signing Jackson Hastings was that the club view him as the ideal partner for Ponga in the halves, but they then need a number one to replace Ponga.

Miller is seen as that player, with the club missing out on Tesi Niu who has signed a deal to move to the Dolphins after being granted a release from the Brisbane Broncos.

It's understood the Sharks have previously knocked back an approach for Miller, however, negotiations are continuing with the Knights wanting to lock Miller into a three-year deal.

A player swap could yet be part of the deal, but even if the Knights don't land Miller, O'Brien revealed on SEN Radio that young gun Bailey Hodgson, veteran Dane Gagai, and recruit Tyson Gamble have also been spending time training at fullback.

“When Kalyn was ruled out for the end of the (2022) season with his HIA issues, the decision was made then,” O'Brien said on SEN 1170 Breakfast.

“If we were ever going to move Kalyn to six, now was the time.

“Essentially, we've had five months to change his training program and he's obviously put some size on.

“He's been training at six all summer and he has been doing a really good job at it.

“We've had a number of guys train (at fullback) over the summer such as young Bailey Hodgson who is finally injury free.

“He's trained there most of the summer alongside guys like Dane Gagai and Tyson Gamble has spent some time back there.

“Strengthening that fullback spot remains a priority for us.”

Ponga has previously trialed a failed move to the halves, but struggled at the back in 2022 both through injury and form.

He did play for Queensland in the number one jersey however, helping the state to a State of Origin victory over New South Wales.

The Knights play their first game in 2023 against the New Zealand Warriors in Wellington.