When Damian McKenzie ruptured his ACL in April and was ruled out of the World Cup, New Zealand’s plans briefly hit a major stumbling block.
Steve Hansen had invested a lot of time in the electric full-back who was set to play a major role in Japan, only for his dream to be scuppered.
It left the All Blacks head coach facing a very much unwanted headache as time was against him in his quest to formulate a game-plan with two playmakers or revert back to Ben Smith, whose best days are behind him.
Moving Beauden Barrett, arguably the best out-half in the world, from his preferred position initially seemed like a mad thing to do, but such has been Richie Mo’unga’s form for the Crusaders over the last two years, things suddenly began to fall into place for New Zealand, even after McKenzie’s injury.
To Hansen’s credit, he stuck by his guns because he had clearly identified from a long way out that in order to give his side the best chance of winning a third consecutive World Cup, he had to have two playmakers on the pitch at the same time.
The ballsy approach didn’t quite fire on all cylinders from the off and instead it has taken Barrett and Mo’unga some time to readjust to the game-plan.
Barrett played plenty of his rugby at full-back in his younger days, but in more recent times, he has produced his best performances in the number 10 shirt.
Mo’unga on the other hand has been a key man in the Crusaders’ last three Super Rugby title successes on the bounce. The 25-year-old benefited hugely from Ronan O’Gara’s time with the Christchurch-based club and this year has scaled even greater heights.
It was no surprise then that Hansen came to the logical conclusion that he simply had to get two of his best players onto the pitch at the same time and in order to do that, Barrett had to shift to full-back.
"I’ve often said if the reward is worth the risk, then take the risk," Hansen explained. "Obviously to replace Beauden at first-five you’ve got to have someone that’s pretty good.
"Richie’s been playing very well for the last couple of years and at some point you want all your good players on the park, and both of them are world-class. In rugby, you always need two good drivers on the park, always have done.
"We’ve always called them first-fives and second-fives. But over time, we’ve introduced a big man at second-five who is not that same type of player that we’ve normally had in New Zealand rugby over the years, so we’ve looked to play him elsewhere."
It makes for a fascinating game-plan that essentially involves Barrett and Mo’unga constantly switching between first and second receiver.
Just when opposition defences think they have figured out the approach, the All Blacks mix it up and in the blink of an eye, turn on the style. South Africa felt the full brunt of that in their pulsating defeat to New Zealand in round one of the tournament.
For the opening 20 minutes, the Springboks frustrated the life out of Hansen’s side and looked like they could go on and beat them.
As they so often do, however, the All Blacks lured them into a false sense of security and with Barrett and Mo’unga seamlessly swapping in and out of the pivot position, the Boks had no answer to their awesome power and speed, particularly on turnover ball.
South Africa were never likely to be able to maintain the ferocious intensity with which they started the game and there is a lesson in that for Ireland.
Building an early lead against the All Blacks is absolutely essential for any team who harbours any realistic ambition of beating them, even if Andy Farrell saw the opening stages of their win over the Boks a bit differently.
"I disagree that they weren’t able to keep up with the intensity simply because the All Blacks did what they do to a lot of teams and they hit them on the break," Ireland’s defence coach maintained.
"The All Blacks didn’t really play that much rugby in that game either and nor should they with the conditions.
"There was a lot of dropped ball, wasn’t there, and very hot and humid in their first game of the competition.
"If you look back at the game the All Blacks hit them on the break and we all know from turnover ball, counter-attack etc, that’s when they’re lethal."
New Zealand have regularly encountered problems when they come up against Farrell’s aggressive defence.
If Ireland can somehow manage to come up with the answers again, it would top every one of Farrell’s other wins over the All Blacks.
Although Mo’unga will almost certainly start at out-half against Ireland in Tokyo on Saturday, Barrett remains the All Blacks’ chief playmaker.
His ability to read the game is phenomenal and that he is coming from full-back, where he generally has a couple of extra seconds to assess the picture in front of him, makes Barrett an even greater threat.
Mo’unga, whose kick-passing game is outstanding, will happily dovetail with Barrett as the pair’s understanding of the system continues to flourish.
"They’re coming along nicely," Hansen recently said of his dual playmakers.
"They’re not the finished article, but we’re happy with how they’re going."
That ominous warning must be heeded because nullifying the threat of Barrett and Mo’unga is crucial to Ireland’s hopes of reaching a first World Cup semi-final.
Why shutting down danger posed by Barrett and Mo'unga is crucial for Ireland
1 – In New Zealand’s opening round win over South Africa, Richie Mo’unga regularly used his excellent kick-passing game to hurt the Springboks on the edges.
With Beauden Barrett in close proximity and offering himself as an alternative option, Mo’unga takes control of the situation and sets Sevu Reece (blue) away with a perfectly-judged kick.
2 – We see a similar scenario unfold here, only this time, Mo’unga (red) steps out of first receiver and allows Barrett (yellow) to take on the responsibility.
George Bridge (blue) holds his width on the left wing, which leaves the Springboks all at sea as they don’t know whether to bite in on Barrett or fold out onto the edge.
3 – Even on the occasions in which Barrett finds himself pulling the strings, Mo’unga is regularly available as the second playmaker off him.
Here we see that in action as Barrett (yellow) finds Mo’unga (red) with Reece again providing the outlet on the right. With so many options on and off the ball, it is a nightmare to defend against.
4 – South Africa’s defence was constantly too narrow as a result of the twin threat of Barrett and Mo’unga in midfield. That is an issue which has also hampered Ireland, so one assumes that Andy Farrell will be working overtime this week. We can see how narrow the Boks get as Mo’unga (red) and Barrett (yellow) again drift in field to call the play. Ireland will have paid close attention to that.
5 – Later on, with the game very much in the balance, the All Blacks brilliantly move through the gears with Mo’unga (red) at first receiver and Barrett (yellow) using his searing pace to get on the outside as he again looks to expose South Africa out wide.