Get the focus part right this week, and the All Blacks should be far too good for the Wallabies.
Don't, and, well, anything is possible.
Japan brings distractions. There's things to do and see at every turn.
For many of the touring squad spending two weeks there, while laying the foundations for next year's World Cup, is new, different, exciting.
Japan's diverse and delicious food; their respectful culture and people offer such contrast from home.
And while some of those differences can be refreshing, for the All Blacks it also brings challenges when there's a test match to be played.
Getting the balance right is important.
There's no secret concealing why the All Blacks always perform at Eden Park. The week, the ground, their record, the Heritage hotel. Familiarity brings comfort.
Even when on the ropes – see the 2011 World Cup final – they get there, no matter what.
Tokyo's Shibuya crossing, with its throng of thousands charging at once, sums up the peripheral for the All Blacks this week.
Everyone wants a selfie.
To generate the necessary interest, revenue and goodwill ahead of next year, breathless commercial duties will also need to be met along the way.
Rugby can fall into the background, somewhat.
In some respects those elements - the different and distracting - draw similarities to Chicago, 2016.
That week the All Blacks found themselves swept up in engulfing celebrations of the Cubs' first World Series triumph in 108 years, and were duly upset by Joe Schmidt's highly prepared, motivated Irish.
This time around it would, potentially, be easy for thoughts to drift ahead to successive headline northern tests against England and Ireland.
This is where the Wallabies come in.
Inflicting dual 38-13 and 40-12 defeats already this year, the All Blacks threatened to get Michael Cheika sacked.
Those wounds still weep but one half time explosion in Argentina appears to have been enough to save his job for now.
In regards to the All Blacks and Wallabies though, no one disputes who is superior.
This year it hasn't been a fair fight. This year, we haven't seen the All Blacks attack click quite like it did against the Wallabies.
For the All Blacks that, too, creates challenges. Can they dismiss those results and evoke the same early-season motivation?
The dangers of not being there mentally were, perhaps, evident in Wellington against the Springboks after their poor form leading into that fixture.
The Japanese heat may take some toll but there's no real excuse from a physical point of view.
The All Blacks, following two weeks out camp, where they work on individual training programmes, should be well rested and ready for their final five-week push that's been a major focus all season.
It's where heads are at which will be telling.
This is effectively a one-off match where the Wallabies have everything to gain. As they proved last season at Suncorp Stadium in the corresponding third test, they have the ability to step up when the pressure is completely off and door left open.
No one really expects them to win in Yokohama.
But the chance to roll the All Blacks and change the complexion of their own season in 80 minutes is enticing.
Cheika may have noted the All Blacks' continued vulnerabilities against organised rush defence; the ability to expose their big men on the short side with quick ball and the need to give Israel Folau ample opportunities to contest ball in the air.
Whether the Wallabies can exploit these areas could be another matter entirely, though.
The return of Brodie Retallick, Liam Squire and Joe Moody sure won't help, and their ropy defence is a concern.
But in a foreign land, where the slate is wiped clean for one match as many other objectives circulate, maybe, just maybe, the door is slightly ajar again.
It all depends on what mental state the All Blacks arrive in.