Campbell Graham has shot himself from 'World Cup depth' to 'a potential full-strength starter' after notching a hat-trick on debut for the Kangaroos - and he's not slowing down.

The Rabbitohs' outside back was the only member of Mal Meninga's 24-man squad not to taste the Origin arena as of yet, however, Graham allayed fears he'd be out of his depth in representative footy, notching 151 metres, six tackle breaks and two line breaks to pair with his three tries.

It was the perfect setting for Graham, who qualifies for both England and Scotland, to make his debut.

The game was played in Coventry, his mother's old hometown, and faced Scotland, where his father grew up in Glasgow.

MELBOURNE, AUSTRALIA - SEPTEMBER 07: Campbell Graham of the Rabbitohs looks dejected after the NRL Qualifying Final match between the Melbourne Storm and the South Sydney Rabbitohs at AAMI Park on September 7, 2018 in Melbourne, Australia. (Photo by Daniel Pockett/Getty Images)

White the Bravehearts are considered a minnow nation in rugby league, an easier opposition didn't help settle Graham's nerves.

“It felt pretty surreal, I was a bit nervous this morning waking up and it started to sink when I got to the ground that I'd be representing the green and gold,” Graham said on Fox League.

“Mal gave us a simple game plan and I knew if I stuck at that and ran hard that opportunities would come and luckily for us they did.

“(Dad) probably has mixed emotions but he'll be all right, he'll just go for the winning team.

“Nah it's good, mum and dad made the trip out here and this used to be mum's home town so it all came together pretty funny but I couldn't have thought of a better debut really.

“I've got a lot family here and for me to represent them it's a huge honour.”

SYDNEY, AUSTRALIA - AUGUST 04: Campbell Graham of the Rabbitohs runs the ball during the round 22 NRL match between the St George Illawarra Dragons and the South Sydney Rabbitohs at Sydney Cricket Ground on August 4, 2017 in Sydney, Australia. (Photo by Mark Kolbe/Getty Images)

Originally set to play for Scotland at the World Cup before Meninga rang, Graham hasn't ruled out representing the nation in the future.

“I haven't played (on the wing) in a while but with the quality of players it doesn't really matter, they make it so easy for you, it's just my job to finish,” he said on Fox League.

“Maybe in a few years I could be representing Scotland but for now I'll be holding onto this Kangaroos jersey as long as I can.”

Despite being snubbed from Origin just months ago, Fox League host Braith Anasta had short but glowing praise for the South Sydney junior.

“I think he's the best defensive centre in the game,” Anasta said on the program.

Graham will be hoping he retains his jersey for Australia's clash with Italy next weekend as the Kangaroos start to ween their 24-man squad down into its best 17, with the Rabbitoh in direct competition with Jack Wighton and Valentine Holmes for a spot on the right edge.