Jack de Belin insists he is capable of several more years in the NRL, as St George Illawarra weigh up the future of the longest-serving player on their roster.

De Belin is off-contract at the end of 2024, having activated an option last year to extend a lucrative $700,000-a-year deal signed in 2020 into a fourth season.

Negotiations are yet to open on any potential extension, with de Belin aged 33 and the Dragons adopting a wait-and-see approach on next year.

But the forward is adamant his body feels far younger than its actual age.

De Belin missed two and a half years of football between 2019 and 2021 through the no-fault stand-down policy, while defending sexual assault charges.

He was ultimately acquitted on one count, while four other charges were dropped following two hung juries.

"Even though I just turned 33, I pretty much missed three years and it has come back to look after me," de Belin told AAP ahead of Saturday's clash with Manly

"I have really looked after my body.

"I have always been big on my recovery and things like that. I could get through at least another couple of good years, minimum."

De Belin is also confident he is capable of playing at the same level he did in 2018 before his time out, when he was a NSW State of Origin lock.

"I still feel like I have plenty to offer. I know my strengths or weaknesses," he said.

"I wouldn't say right now I'm playing my best footy, but there's always plenty to build on as the year goes on. I have always been a player that builds into it.

"You probably don't have an opportunity to show as much when you're not winning.

"In 2018 we had an unreal side and we were riding high. I feel like how you play personally is a portrayal of how the team is playing.

"With regards to my body, I still feel fantastic, it just hasn't really been able to show because we haven't been able to get the results as a team."

De Belin is easily St George Illawarra's longest-serving current player, after debuting in 2011.

Blake Lawrie, who debuted in 2017, is the next closest.

De Belin is one of 14 Dragons off-contract for next year, as new coach Shane Flanagan begins to shape his roster for his time in Wollongong.

Included in the list are fullback Tyrell Sloan and second-rower Jaydn Su'A.

"I'd love to stay here, that's my plan. I've always wanted to be a one-club player," de Belin said.

"I haven't really been spoken about it with my manager yet. He just said play good footy, so that's all I've been really worrying about."