Aaron Cruden will neither share nor shake the nation's nerves when he slips comfortably into Dan Carter's boots tomorrow night.

It's a stark contrast to the mood eight months ago when there was widespread pandemonium at what might happen to a Carter-less All Blacks.

Since then Cruden, and the rugby public, have matured somewhat with a World Cup win and a sparkling season with the Chiefs smoothing furrowed brows.

The secret for both parties, it seems, has been to relax.

And though six changes to the All Blacks side, including the absence of Carter and No8 Kieran Read, will give Ireland hope, they will not see Cruden as a weak link.

"When I first came in I was really nervous," the 23-year-old said yesterday after being named to start at first five-eighth for the third and final test against Ireland.

"[Then] I changed a lot of my techniques and routines in the way I approached things because I didn't want to not note everything down or miss something and let the team down.

"I think coming in now I'm a lot more relaxed. I'm stuck in my routine that's been working for me for the last couple of years.

"I'm just doing that no matter what team I'm playing for, whether it's Manawatu, the Chiefs, or the All Blacks."

What a contrast to the bloke who made a nervy first test start against Australia in Sydney in 2010, pulled after 61 minutes as the All Blacks scraped home 23-22.

It seems a lifetime ago. Cruden stepped up during the 20-6 World Cup semifinal win over the Wallabies and hasn't looked back.

In fact, his move from the Hurricanes to the Chiefs has taken his game to the point where the shadow of Carter, though still there, is no longer the stuff of nightmares.

Cruden still sees the man he's replaced as the "best in the world", but he's now comfortable with the task of putting Carter under pressure.

That's a big change from the then 21-year-old who was just glad to get a run when he made his test debut against Ireland two years ago with a breezy 27 minutes during the 66-28 win in New Plymouth.

Significantly, Cruden's fourth start in 10 tests will be the first time he has taken the goal-kicking duties into an international.

Notably, he puts his Super Rugby success – he's running at 82 per cent this season – down to less practice.

"In past years I've been almost goal kicking every day and if it wasn't really working I'd try and change something to help my technique and it seemed to make it worse.

"This year I've just relaxed about it and I'm set in my technique and it [the ball] seems to be going over the sticks, which is great."

Barefoot at the team hotel, Cruden cut a laidback figure.

After a stressful Hurricanes campaign in 2011, he's enjoying the calming influence of Chiefs coach and mentor Dave Rennie, who gave him his start with Manawatu.

"For such a young coach Rens has that aura about him. He can put guys at ease; he's constantly talking [to them] about their games and off-field life as well, just getting back to enjoying footy which is great."

Of course Cruden, and his burgeoning combination Chiefs team-mate Sonny Bill Williams, will need front-foot ball to be as effective in the test arena.

Then again, the All Blacks have never lost with Cruden in their squad and he will not be up nights worrying he won't do a decent job.

- © Fairfax NZ News