St George Illawarra playmaker Jayden Sullivan says he has trained exclusively in the halves as he eyes the opportunity to become the club's long-term five-eighth.

The 20-year-old, who signed a three-year extension last week, has been restricted to six NRL games over the past two seasons.

And with Adam Clune and Corey Norman having left the club, the door is open for Sullivan or fellow youngster Junior Amone to partner Ben Hunt in the halves come round one of the 2022 season.

"I'll play anywhere but (it's preferable) if I can play in the halves," Sullivan said on Tuesday.

"I want to put my best foot forward and do what's best for the team.

"I've only trained at 6, if I play 6, I play 6 but I'll play anywhere, just as long as I'm in the team."

Sullivan enjoyed cameos at hooker last season with Andrew McCullough injured and many of the Red V's top-line players suspended after Paul Vaughan's infamous barbeque.

Moses Mbye is expected to cover the utility role from the bench for Anthony Griffin's side after joining the Dragons from the Wests Tigers.

Sullivan came through the same junior system as Amone and fullback Tyrell Sloan, with McCullough hopeful the young trio could have a big impact on the club's fortunes in 2022.

"They come in each day and there's no whingeing or moaning, they want to get better," McCullough said.

"They ask questions, train hard and do the best they can.

"Having that exposure last year - it was a bit of a tough run for us - it gave those kids an insight into what it's like in the NRL.

"Hook's (Griffin) always ramming into them about being professional and the pressure is off for them to perform.

"That builds up and they'll make mistakes on the way but that's all part of learning."