Rugby Championship: Babies, injuries, visa issues - Why five All Blacks stars were left in New Zealand

Ten tests in 12 weeks, navigating quarantine regulations in multiple countries, a global pandemic and a host of senior players missing through family commitments. The All Blacks have set off on a tour unlike any other in the modern age, one that promises to challenge their mental and physical resolve.

As he prepared to depart for Perth with his initial 35-man squad on Thursday, All Blacks coach Ian Foster made it clear the team was ready to embrace every hurdle they will face. In the same breath, he was real about the difficulties involved in being away from home for 14 weeks, and the issues integrating additional players.

"This is probably a tour like none other in the professional era," Foster said. "Everyone has had to say goodbye to families but, overall, we're very excited about it and we know when we get to Perth we can settle down and address the challenges ahead one-by-one."

Sam Whitelock and Aaron Smith will miss the start of the All Blacks' tours. Photo / Photosport

The All Blacks left stand-in captain Sam Whitelock, Richie Mo'unga and Aaron Smith behind as they are expecting babies in the coming weeks. Foster confirmed those senior figures will not only miss the third Bledisloe Cup in Perth on Sunday, September 5, but probably the two Rugby Championship tests against the Pumas to follow due to Queensland's two-week hotel quarantine stipulations for those travelling from New Zealand.

"I'd be surprised if it wasn't three. I don't really want to say too much beyond that," Foster said. "We don't want to put any expectation or pressure on families. It's pretty extraordinary times.

"We'd prefer to have all our experienced players on deck but this is a chance to grow a bit of depth by necessity.

"We're massively supportive of the decisions they've made for their families. I know the team is 100 per cent behind them, and I know they're very keen to jump on a plane as soon as they can. It's been difficult saying goodbye to them, but the reality is that's what we have to do in these times.

"The fact it would normally mean people missing one test and now they might miss three or four complicates the whole issue, but the solution is pretty simple."

Ian Foster says the All Blacks are heading off on a 'tour like none other'. Photo / Getty

Lock Scott Barrett, likely to start alongside Brodie Retallick next week in Whitelock's absence, is expecting his first child later this year too. At this stage, with the All Blacks securing MIQ spots from November 23, he may miss the birth.

"Yes there is a chance he can't come back," Foster said. "There's no certainty at all in that world. Clearly as a family they're looking at opportunities and we're looking at them too, but there's no guarantees."

The All Blacks squad features six loose forwards but Highlanders blindside Shannon Frizell has been left in Dunedin after being charged with two counts of male assaults female and another of common assault earlier this year. He has been offered diversion by the police and is not likely to be convicted over the matter, but this will be determined at a hearing on September 21.

Foster confirmed those charges prevented Frizell from gaining a visa to enter Australia.

"He's got aspects to work through regarding his court case. We're really confident he will but in the meantime he's got some things to do with that before he can come over."

Dane Coles will join the All Blacks in Queensland for the Rugby Championship once he has recovered from his calf complaint, while injured captain Sam Cane is not due back until late September and therefore remains on track for the end of year tour.

Dane Coles and Richie Mo'unga following the All Blacks' test against Tonga in July. Photo / Photosport

Foster is yet to publicly name a new skipper but in the absence of Cane, Whitelock and Smith, the Herald understands Ardie Savea is likely to captain the All Blacks for the first time against the Wallabies next week.

Beyond the Wallabies, Foster will be sweating on any serious injuries to his squad as bringing over replacement players is far from straightforward.

Anyone joining the initial squad must be double vaccinated, and must then stay with the team for the remainder of the season. New Zealand's lockdown has also halted the NPC, leaving all players in isolation.

Foster is not expecting a warm welcome in Perth after the All Blacks delayed their departure last weekend, forcing the final Bledisloe to be rescheduled. The fallout that followed is sure to spark up again once the All Blacks land on foreign soil.

"I don't think they'll fall in love with us straight away. We're really satisfied with the decisions that have been made administratively. Now we know with certainty that South Africa and Argentina are all turning up in Australia so we know there is going to be a Rugby Championship.

"There might be a bit of explaining to do in some ways, but ultimately we can't control that. We're really confident in the decisions that have been made on our side of the Tasman and all signs point to common sense has prevailed. Hopefully we'll resort to the normal levels of hostility you normally get for a Wallabies and All Blacks game."

Aggravated Australians is but the first point on the long list of challenges Foster and the All Blacks will confront in the coming months.

Initial All Blacks travelling squad

Forwards

Hookers: Asafo Aumua, Samisoni Taukei'aho and Codie Taylor.

Props: George Bower, Ethan de Groot, Nepo Laulala, Tyrel Lomax, Joe Moody, Angus Ta'avao, Karl Tu'inukuafe and Ofa Tuungafasi.

Locks: Scott Barrett, Brodie Retallick, Patrick Tuipulotu and Tupou Vaa'i.

Loose forwards: Ethan Blackadder, Akira Ioane, Luke Jacobson, Dalton Papalii, Ardie Savea and Hoskins Sotutu.

Backs

Halfbacks: Finlay Christie, TJ Perenara and Brad Weber.

First five–eighths: Beauden Barrett.

Midfielders: Braydon Ennor, David Havili, Rieko Ioane, Anton Lienert-Brown and Quinn Tupaea.

Outside backs: Jordie Barrett, George Bridge, Will Jordan, Damian McKenzie and Sevu Reece.