Three years after his Sydney stumble, Aaron Cruden feels he has found his feet in Test rugby.

Saturday night's Rugby Championship opener against the Wallabies is the 24-year-old's second Test in Sydney - both coming in the wake of an injury to Dan Carter.

The difference between the two occasions is profound for the brilliant Chiefs No.10, who was making his starting debut in 2010.

Struggling badly with his option-taking and kicking, he was hooked with 20 minutes remaining and the All Blacks trailing by 13 points. They fought back to win 23-22.

"I was really nervous, I probably didn't play my natural game. I thought I had to change a few things coming in to the highest level of rugby," Cruden said.

"The last few years have shown me that I can just get out there and do my thing.

"I was picked for a reason and if I change that, I'm not doing myself justice, or the jersey."

Cruden has been in a losing team just once in 22 Tests.

His match control and ability to break a game open is at the heart of a similarly successful run at the two-time champion Chiefs, where his confidence has expanded and winning has become "addictive".

A chink in the Cruden armour was apparent in the recent final against the ACT Brumbies, where he missed three relatively kickable shots at goal, but he says spending time with All Blacks skills coach Mick Byrne has reset his radar.

They realised he had been getting too square on in his approach and worrying too much about the outcome rather than the process.

However, Cruden hopes it is attacking play, rather than goalkicking, which will make the difference on Saturday.

"For us, it's about playing what we see, backing our instincts," he said.