Victor Vito flicks a ball over his head during the All Blacks' captain's run.

Captain Richie McCaw and his deputy Conrad Smith at the All Blacks' captain's run at Eden Park.

Dan Carter gets in some long-range kick attempts at goal at Eden Park.

Tony Woodcock and Sam Whitelock practice scrummaging at an All Blacks training session in Linwood ahead of the second test in Christchurch.

Hosea Gear and Ma'a Nonu take time out at an All Blacks training session in Linwood ahead of the second test in Christchurch.

Sonny Bill Williams on the charge at a training session in Linwood as the All Blacks prepare for the second test in Christchurch.

Sonny Bill Williams and Tamati Ellison signs autographs for fans at Pak n Save on Wainoni Rd in Christchurch ahead of the second test.

Ireland's Mike Ross and Sean Cronin doing some scrummaging during training in Auckland.

The Irish rugby squad continues training in Auckland after the first test.

Sonny Bill Williams passes the ball to a team-mate during the All Blacks' final run.

All Blacks train with the New Zealand Black Sticks in Hamilton. Owen Franks, Cathryn Finlayson and Piri Weepu play touch.

All Blacks train with the New Zealand Black Sticks in Hamilton. Benjamin Tameifuna shows his dexterity.

All Blacks train with the New Zealand Black Sticks in Hamilton. Ella Gunson shows Sonny Bill Williams hockey stick basics.

All Blacks train with the New Zealand Black Sticks in Hamilton. Aaron Smith plays a warm up game with Sam Harrison.

All Blacks (from left) Ma'a Nonu and Zac Guildford perform the haka with Melville High School students during a visit to the school.

All Blacks (from left) Zac Guildford, Tamati Ellison and Ma'a Nonu are welcomed onto the Melville High School marae.

Victor Vito, Liam Messam and Sonny Bill Williams during the All Blacks rugby training session at Beetham Park.

Victor Vito, Liam Messam and Sonny Bill Williams during the All Blacks rugby training session at Beetham Park.

Julian Savea jumps high against assistant coach Ian Foster during the All Blacks training session at Beetham Park.

Zach Guilford jumps high against assistant coach Ian Foster during the All Blacks training session at Beetham Park.

All Black coach Steve Hansen, left, and Assistant Coach Ian Foster, right, during the All Blacks training session at Beetham Park.

Julian Savea, Zach Guilford and Ma'a Nonu during the All Blacks training session at Beetham Park.

Israel Dagg jumps high against assistant coach Ian Foster during the All Blacks training session at Beetham Park.

Sonny Bill Williams and Zach Guilford during the All Blacks training session at Beetham Park.

Richie McCaw and Steve Hansen talk at the All Blacks captain's run ahead of the third test.

Dan Carter is out with a hamstring injury in a dramatic turn of events that has turned the All Blacks' third test against Ireland into anything but a dead rubber.

All Blacks coach Steve Hansen has fearlessly made six changes to the side that started the 22-19 win in Christchurch, with lock Luke Romano to make his debut in place of Brodie Retallick in a revamped pack.

In a new-look loose trio, Richie McCaw takes over at No 8 from Kieran Read, who has been ruled out due to concussion, with Liam Messam at blindside and Sam Cane on the openside in what will be his first test start.

PETER DRURY/Fairfax NZ UNLEASHED: Dan Carter's hamstring injury means Aaron Cruden will wear the No 10 jersey.

In the backs, Aaron Cruden will wear the No 10 jersey after Carter pulled up lame after training on Tuesday, while Hosea Gear and Ben Smith go on to the wings.

Retallick and loose forward Adam Thomson drop to a new-look reserves bench that includes Taranaki rookie Beauden Barrett, Highlanders utility back Tamati Ellison and veteran hooker Keven Mealamu.

Wings Zac Guildford and Julian Savea drop out of the squad altogether.

Hansen indicated the changes were in part because his side had not performed to expectation in Christchurch.

The All Blacks by their own admission weren't happy with the way they performed on Saturday and in part this was a credit to the way the Irish played, he said. "They have laid down the challenge and the key will be now how we respond."

Of most significance is the absence of Carter, who will undergo further tests in the next few days to determine how long he will be out of rugby.

Cruden makes his fourth test start and first since the World Cup final, and where such a selection might previously have sent the nation into panic attacks it is unlikely to cause more than a flutter.

Cruden, 23, is a readymade replacement on a ground he has made his own this season for the Chiefs and will reunite his successful combination with second five-eighth Sonny Bill Williams.

The selection of Romano, 26, may be greeted with less ease. It suggests an effort to add grunt to a scrum that struggled badly last time out, but it's unclear why Thomson, who broke his nose in Christchurch, has been relegated to the bench.

It may be to add some energy and ball-carrying finesse with Messam champing at the bit in what will be his first test since he started at No 8 against South Africa during last year's Tri-Nations. That was also the last time Gear wore the black jersey.

Playing his 10th test, it will be only the third time Messam has started at blindside.

And it will mean McCaw wears the All Blacks' No 8 jersey in what will be his 100th test start of his career, a feat achieved by only two other forwards, South Africa's Victor Matfield and England's Jason Leonard.

Mealamu returns for the first time since injuring his calf playing for the Blues in early April, then missing the first two tests as a precaution.

ALL BLACKS: Israel Dagg, Ben Smith, Conrad Smith, Sonny Bill Williams, Hosea Gear, Aaron Cruden, Aaron Smith, Richie McCaw (capt), Sam Cane, Liam Messam, Sam Whitelock, Luke Romano, Owen Franks, Andrew Hore, Tony Woodcock. Reserves: Keven Mealamu, Ben Franks, Brodie Retallick, Adam Thomson, Piri Weepu, Beauden Barrett, Tamati Ellison.