After enduring three wrestling sessions during his first week of training with Sydney Roosters, James Tedesco was thinking 2018 wasn't going to be much fun.

By the end of the same season, Tedesco has achieved State of Origin success with NSW, a premiership with the Roosters and selection as Australian fullback for Saturday's Test against New Zealand at Mount Smart Stadium.

"There have been pretty good accomplishments this year but this tops it all off," Tedesco said of his Test debut. "I wanted to be successful and have a good year but I didn't expect it all to come quickly."

In fact, Tedesco admits he had some concerns about the strong emphasis placed on defence by Roosters coach Trent Robinson and assistant Craig Fitzgibbon when he joined the club from Wests Tigers at the start of the season.

Robinson wanted Tedesco to take on an organising role behind the defensive line, just as Anthony Minichiello had performed for the Roosters during his career and Billy Slater did at Melbourne.

Coincidentally, Slater took over from Minichiello as the long-term Kangaroos fullback and Tedesco is now aiming to make the Australian No.1 jersey his own after being given his chance against the Kiwis.

The 25-year-old concedes he is not yet the "complete" fullback and issued an ominous warning for rival clubs by declaring both he and the Roosters would be aiming to improve their attack next season after focusing heavily on defence this year.

"Robbo made it clear from the start with him and Fitzy that defence would be our No.1 priority," Tedesco said. "The first week we had three wrestle sessions and I was thinking this was not that much fun but everyone said at the start it would pay off.

"I worked hard with Robbo and the time and effort we put into defence has been the biggest change for me.

"Robbo was speaking after the season and [he said] the defence he wanted to get out of me has hit 100 per cent where he wanted to get to [but] attack didn't hit 100 per cent. That's the exciting bit heading into next year, I still have a bit left to improve on in attack.

"I feel that too. I feel like there is more for me to exploit. I got to where I wanted to be by the end of the year but there are still areas I could improve and get involved more. We have a similar team next year but it won't be a case of being comfortable, I will be straight into it."

Tedesco said he felt great satisfaction from what he had managed to achieve this season – and not just because he is now the proud owner of a Brad Fittler Medal (as NSW Origin player of the series), a premiership ring and his first Kangaroos jersey.

Each of those are rewards for the work he did with Robinson to adapt his game.

"I don't think many coaches think how Robbo does with how detailed he is [about] organising a line, communication and against different teams, having different strategies. I don't know many coaches would teach it with the way he does.

"Not many fullbacks would've been able to learn the stuff I did. That was good for my confidence, trying to be the complete fullback. I am pretty proud of my year, to come over to the Roosters and winning the premiership and now to be playing for Australia."

After finally being given the chance to wear the No.1 jersey for the Kangaroos, Tedesco wants to establish himself as Australia's regular fullback for years to come – as Slater had done.

"I think everyone has the goal of playing for Australia but I knew with Slater retiring that if I had a good year at the Roosters that an opportunity would come up and I was really happy with how I played this year," Tedesco said.

"He held the jersey for a number of years and dominated the game but I am 25 now and I think for myself there is a chance to hold the No.1 jersey for a while.

"It is not going to come easy but I think I can get that started by training well this week and having a good game on Saturday."

While there has been a changing of the guard in the Australian team following the retirement of Slater and Johnathan Thurston and the decision of Cooper Cronk and Cameron Smith to stand down from representative football, Tedesco has no shortage of familiar faces in the Kangaroos squad.

Roosters captain Boyd Cordner will lead Australia for the first time against the Kiwis on Saturday, while five-eighth Luke Keary and centre Latrell Mitchell are also making their Test debuts, along with South Sydney hooker Damien Cook.

"I think if it was an older experienced side I would feel a bit shy but being around guys I have played with before and I feel comfortable with it doesn't feel like I am a debutant," Tedesco said.

"It is a young squad that we have got here so there is a good opportunity to keep this team for a while."