Apisai Koroisau carried the signature of suspended teammate Issac Luke on his right wrist in the Rabbitohs' dramatic Grand Final.

Koroisau from GF hero to Panthers back-up

He was South Sydney's unlikely grand final hero, a speedy ring-in who displayed maturity beyond his years in the club's historic drought-breaking premiership triumph.

But just two months into a move to Penrith, Apisai Koroisau is ready to start from the bottom – even if it means being the understudy to star no. 9 James Segeyaro. 

"At the time when I signed, he was still sitting behind Kevin Kingston, but I've shaped my mentality to fit within the team," Koroisau told NRL.com.

"Wherever [coach] Ivan [Cleary] sees that, whether it's off the bench or backing up in case he gets injured, it doesn't bother me. I'm here to better my skills, and get better every day."

But the 22-year-old has also stated his case to play off Ivan Cleary's bench, revealing how Rabbitohs coach Michael Maguire was developing him as a playmaker as well as a dummy-half at Redfern. 

"I'm not too sure about over here, but over at South Sydney, I was playing that role when I was back in reserve grade. It's not a new position to me, but I definitely played half there. Then I was seen as a hooker coming into first grade," he said. 

"Maguire played me at half against the Gold Coast (in round 17) because Adam Reynolds got injured. So I'm a bit of a utility. I definitely see it as another opportunity, another pathway."

Koroisau was the Panthers' only notable signing over the summer, putting pen to paper on a two-year deal earlier this year to fill the gaping hole left by the retirement of experienced rake Kevin Kingston. 

And while staying with the eventual premiers was an obvious option, Koroisau recalled how he was swayed by a club that was beginning to flex its muscles as a premiership force. 

Asked what the major factor was in his decision to leave South Sydney, he said: "Just the way Penrith were conducting themselves, to be honest. They seemed a bit like a club on the rise, they were going places.

"And like South Sydney, I wanted to be a part of that. I heard really good things about Gus [Phil Gould] and Ivan and I really wanted to come in, better my skills here and hopefully win another grand final."

A second premiership ring would be a stunning start to the career for the Fijian international, whose 14-game rookie season culminated in a shock call-up at the expense of the suspended Issac Luke. 

"Michael Maguire gave me a call and told me to be ready just in case, but I didn't really know until Tuesday night. I felt really bad, obviously. I'm really close with Issac Luke. Something like that to be taken away from someone is incredible," he said. 

"All I was thinking was that I had a job to do and I had to go out there and do it. I definitely had thoughts about giving the ring to him, because it obviously would've meant more to him than me. But you can't take this feeling away that I got from actually winning the grand final and playing in it.

"It was a blur until I watched it over again. I watched it a couple of times actually. Some of the feelings that I experienced during that game was just insane, especially that final whistle blowing, looking at the crowd, seeing old men cry, seeing so many people enjoy happiness was something that's hard to explain. It was definitely one of the greatest moments of my life."