Rabbitohs veteran John Sutton.

Off-contract South Sydney veteran John Sutton has returned to his 2014 premiership-winning form and is in line to reach the biggest milestone of career.

The one-club player is just three matches away from hitting his 300th NRL game after a 15-year stellar career and is convincing teammates he can continue to thrive in 2019 and beyond.

Rabbitohs halfback Adam Reynolds said the 33-year-old's form suggested he still had years left in him.

"He's a vital part of our team and I'd love to see him go around for a couple more years," Reynolds said.

"He was our captain when we won the grand final and is our longest serving member at the moment.

"The boys love having him around and there a lot of respect for him on and off the field.

"He's in fantastic form and he's doing a great job for us this year so we couldn't ask for anything more from him."

Sutton's future after this season is still unclear but the second-rower said his focus was simply on making the most of his time left in the game.

"I've just got to keep doing my job, it's a pretty simple role that I have here. Just running the ball and keep making my tackles and everything else comes off the back of that," Sutton said.

"I'm just enjoying my football at the moment, it's going really well and I just hope to keep continuing the way I'm playing.

"I thought about it the last couple of years more than ever that it's going to end soon so that's why I'm making sure I'm enjoying it here week to week, hanging out with the boys and ripping in on the weekends."

The Bunnies head to Barlow Park in Cairns on Sunday to take on North Queensland in a fixture they have lost for the past two seasons.

"It's great going up to Cairns, we haven't been too successful the last couple of years up there but it's a great game up there and always packed with a lot of Souths fans," Sutton said.

"The Cowboys haven't been travelling too good but they've got some classy players in their team so we need to be at our best.

"They have Johnathan Thurston, one of the greatest players ever to play the game, and when he's playing they're a good team so we have to make sure we shut him down."

The Rabbitohs were low on numbers at training in the lead-up to the representative weekend with the Burgess brothers jetting off to Denver on England duty and Greg Inglis, Damien Cook, Dane Gagai and Angus Crichton taking part in Sunday's State of Origin II.

John Sutton scores for the Rabbitohs.
John Sutton scores for the Rabbitohs. ©Shane Wenzlick/NRL Photos

Sutton said with the week-long turnaround before their round 16 clash would put all seven players in contention for selection.

"All the boys that played representative football will hopefully be rested up well," Sutton said.

"We aren't playing until Sunday so we will get a couple of sessions with all boys back in.

"Looking forward to them coming back and ripping in, they've all played really well over the representative round so it will be good to have them back."