On the eve of his return for the Hurricanes - their quarter-final win over the Brumbies in Canberra - Coles spoke of his worry at the symptoms which at one stage prevented him from going to matches to support his team as he couldn't handle noisy environments.
"I got into a bit of a dark place," he said in July. "I couldn't even do any exercise and I had conversations with my partner about retirement. It was really hard. I love playing footy, it's my job and I couldn't do it."
He is the only change to the starting XV following last Saturday's 54-34 thrashing of the Wallabies which has allowed the All Blacks to put one hand on the Bledisloe Cup for another year.
Kane Hames is the loosehead prop cover on the reserves bench following Wyatt Crockett's head knock last weekend, with Scott Barrett replacing fellow Crusaders player Luke Romano on the bench as lock cover due to what has been described by the All Blacks as a "minor foot niggle".
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The selection of the slightly more mobile Barrett, considered a first-choice lock at the Crusaders alongside Sam Whitelock, will also assist the All Blacks in keeping a higher tempo in the final quarter on Saturday after problems in this area over the past four tests.
"It's been great to be back home in New Zealand and we've had a great week's preparation here in Dunedin," All Blacks coach Steve Hansen said. "While we were very happy with the way we played for periods of the game in the first test, there were also moments where we weren't so crash hot.
"However, this is a new week and we're well aware that we'll have to be better in all areas of our game, and we've concentrated on those areas we want to improve. Once again, a good start will be important."
Hansen said the team were looking forward to playing under the roof again.
"[It] means we should see a high-speed game, which should suit both teams and create an entertaining match that fans won't want to miss. I know the team itself is looking forward to Saturday as it's another opportunity to grow and develop as a group."
Whitelock will be starting his 90th test, making the 28-year-old the most capped All Blacks lock in history.
All Blacks team to play Australia at Forsyth Barr Stadium on Saturday:
15. Damian McKenzie
14. Ben Smith
13. Ryan Crotty
12. Sonny Bill Williams
11. Rieko Ioane
10. Beauden Barrett
9. Aaron Smith
8. Kieran Read (c)
7. Sam Cane
6. Liam Squire
5. Sam Whitelock
4. Brodie Retallick
3. Owen Franks
2. Dane Coles
1. Joe Moody
Reserves: Codie Taylor, Kane Hames, Ofa Tu'ungafasi, Scott Barrett, Ardie Savea, TJ Perenara, Lima Sopoaga, Anton Lienert-Brown.