All Blacks v Wallabies: Captain Sam Cane in doubt as multiple changes likely for All Blacks' second test against Australia

The All Blacks seem set to embrace a change of captain for their rematch with the Wallabies at Eden Park after Sam Cane took a limited part in Tuesday training following his head knock in Melbourne last week.

All Blacks forwards coach Jason Ryan gave little away when he spoke to media after training at Mt Smart Stadium but the sight of Cane on the sideline in track pants for the latter stages of the session suggests the skipper is unlikely to feature at a sold-out Eden Park on Saturday.

Cane self-reported his head knock during the first half of Thursday's great escape at Marvel Stadium. He was replaced by Dalton Papali'i in the 24th minute, and did not return to the field.

While All Blacks coach Ian Foster indicated Cane passed his HIA later that night, lingering symptoms may prevent him from playing this week.

World Rugby protocols subject all players who fail HIA assessments to 12-day standdowns. Whether Cane falls into that category remains unclear but second five-eighth David Havili, despite taking some part in Tuesday training, is expected to be ruled out on that basis after his head knock in the 14th minute last week.

The All Blacks have adopted a cautious approach to concussion concerns in recent times. It would, therefore, be a surprise if Cane or Havili feature at Eden Park.

"The boys with HIAs are going through their protocols," Ryan said. "It's a World Rugby protocol and a protocol for the All Blacks. We have got the utmost interest for our players so we'll do everything we can to get that right. There will be no risks at all."

Sam Cane suffered a head knock in the first Wallabies test. Photo / Photosport

Cane has started all eight tests – leading the All Blacks to four wins and four losses - this season, but his probable absence this week could force another loose forward reshuffle.

Blues skipper Papalli'i looms as Cane's natural replacement, with Ardie Savea likely to assume the captaincy in his return to No 8 after missing last week's knife-edge victory to attend the birth of his third child. Sam Whitelock is Cane's other possible captaincy replacement.

There could be a third change to the loose forwards, too, with Shannon Frizell in line to reclaim the blindside role, providing he proves his fitness after sitting out the Melbourne win with a minor rib injury.

"Shannon has had that niggly rib so he's got to get through Thursday and see how that pans out," Ryan said. "Ardie has come in fresh and selectable. He's got a lot of mana in the group. He's fresh here but he's just had another baby so I'm sure he's had a few sleepless nights. He's great for us. We get a lot of energy from him in our group. That week off will definitely sharpen him up so he'll be raring to go."

Ryan spoke glowingly of Scott Barrett's performances this season but his selection at blindside appears better suited to the teams that favour a slower pace and live through the success of their set piece.

Returning Frizell to No 6 would offer the All Blacks more punch from a ball carrying perspective. And after the Wallabies enjoyed success in that area through loose forwards Rob Valetini, Pete Samu and Rob Leota, the latter now out for the year after rupturing his Achilles, Frizell's presence could be hard to ignore.

Shannon Frizell in action against Argentina. Photo / Photosport

Should the All Blacks opt to reinstate Frizell alongside Papali'i and Savea, Barrett could return to partner Whitelock in the second-row with Brodie Retallick shifting to the bench.

"I'd say he's probably our best performing All Blacks forward to be honest," Ryan said of Barrett. "He's been outstanding in every role. He's a huge part of our forward pack. He's playing some really good rugby. He's been consistent. That's followed on from his Super Rugby season and he's a pivotal part of the All Blacks team."

With Havili expected to be sidelined, and Quinn Tupaea suffering a season-ending knee injury as a result of Darcy Swain's ugly cleanout attempt, Jordie Barrett is favoured to start at second-five with Beauden Barrett possibly shifting to fullback.

Roger Tuivasa-Sheck, who trained with tapping over the ear he cut while playing for Auckland last Saturday, may come onto the bench.

It's clear the All Blacks are demanding more consistency from their forward pack, as they are the whole team, after delivering another patchy performance that culminated in blowing an 18-point second half lead.

"They had their moments, as the whole pack did," Ryan said of last week's revamped loose trio that featured Hoskins Sotutu, Barrett, Cane/Papali'i and Akira Ioane. "There were times we had really good intensity in that area and times we could have been better. Like any combination it takes a bit of time and with changes you have to find your rhythm early, especially in test matches."

Locked at the top of the Rugby Championship with the Springboks, but with a superior 13-point differential, the All Blacks must defeat the Wallabies in their quest to claim this year's title.

"100 per cent it's a final," Ryan said. "I think there were a couple of comments from someone about it being a dead rubber. I don't know where that would come from. It's a New Zealand-Australia test match at Eden Park and there's a lot on the line. We're treating it like a final and we've prepared accordingly to respect that."

A bonus point victory over the Wallabies, who last won at Eden Park in 1986, would ensure the Springboks must achieve the same feat in their return test against Argentina in Durban and overhaul the All Blacks' points advantage to snatch the title.

"It's definitely in the thinking but it's not front of mind you've got to win the game. That's how we've approached it."