On Friday night (CI time) the All Blacks meet the British and Irish Lions in a third Test decider at Eden Park that shapes as a contest for the ages. The touring side is chasing just its second ever series victory over New Zealand; while Hansen's men are looking to continue a 38-test, 23-year winning streak at their Auckland fortress, as well as avoid back-to-back home defeats for the first time since 1998.
After Friday’s 24-21 second-test victory by the Lions in Wellington - just their second win over the All Blacks in their past 14 encounters - Warren Gatland's men have given themselves a sniff of creating some pretty special history. The 1971 Lions are recognised far and wide as the finest of their brethren - the only men to have knocked over the mighty New Zealanders in a series. Now they just might have some company.
It's unlikely that Gatland will consider many, if any, personnel changes after his men timed their run perfectly to haul in the undermanned All Blacks at the Cake Tin. His Wellington heroes deserve a second shot at completing a storybook come-from-behind series victory.
But Hansen, on the other hand, has some big decisions to make, especially in his backline.
With Sonny Bill Williams suspended and Ryan Crotty unlikely to have recovered from his first-Test hamstring strain, a midfield reshuffle will be required. And this is where Hansen must be bold.
After Crotty was injured at Eden Park, the All Blacks coach added Crusaders youngster Jack Goodhue to his squad. Now, in the wake of Wellington, he has also called in previously unwanted Highlander, and 23-test veteran, Malakai Fekitoa.
That leaves Anton Lienert-Brown, rookie Ngani Laumape, who played 54 minutes off the bench on Saturday night when Williams was sent off, Goodhue and Fekitoa in contention for the two starting midfield spots, and potentially one bench one.
You could also throw 20-year-old utility Jordie Barrett into that mix, though he's viewed more as a fullback option in the All Blacks at this early stage of his career.
By rights Hansen should send out Laumape and Lienert-Brown from the off, and decide between the others for a bench spot. Laumape is, after all, his top-ranked fit and available second five-eighth.
But Hansen has a better option. He should move Lienert-Brown to No 12, where he is just as adept, and pick Fekitoa as his starting centre. That stands out as a Test-hardened, proven combination up to a challenge as big as Saturday night will be.
That would give him his best chance of securing the victory he needs to deny these Lions their slice of history.
Remember, Fekitoa is really only his sixth-choice midfielder. Williams, Crotty, Lienert-Brown, Laumape and Goodhue have all been selected ahead of him. So it's going to take a leap of faith.
The 25-year-old Highlanders star is said to be on the verge of a move to Toulon in France, with his latest All Black snub thought to be the catalyst for that. But could Fekitoa be handed a chance to revive his Test career? Could he then reconsider his decision to bolt for France when his New Zealand contract finishes at the end of this season?
If Hansen makes the big call, Fekitoa might just be given the chance to do just that.
I'd pick Fekitoa ahead of Laumape and Goodhue because this is an occasion that demands experience. Also because he has been playing pretty damn well for the Highlanders, and was probably unlucky to slide so far down the pecking order.
Laumape did some good things on Saturday night (mainly carrying the ball) and some not-so-good things (on defence). but he might be best used for impact off the bench. And this is not time, surely, to be throwing Goodhue in for his first test experience.
The back three mix will also come under the microscope. Waisake Naholo will need to prove he's over the head knock he took from Sean O'Brien's swinging arm, and Julian Savea looms as a potential replacement. Izzy Dagg should stay at fullback, never mind his inability to halt Taulupe Falatau in his tracks.
But all things being equal it's Fekitoa who looms as the man for the occasion. Recently he bared all for ESPN The Magazine's annual Body Issue. On Saturday night he may need to reveal even more of himself with a Lions series on the line.
- Stuff/ Marc Hinton