When news broke that Dan Carter would miss the remainder of the 2011 Rugby World Cup, it was something of a national tragedy in New Zealand. The All Blacks were amidst a home World Cup campaign with the need to win greater than ever, having not hoisted the trophy since 1987.
Carter was seen as integral to that campaign, and to lose him with no obvious back-up left many pundits thinking the worst.
It is hard to believe how far New Zealand's next tier of fly-halves have come since then. But come that far they have, and now with arguably the greatest depth in the position of any country in the world, there is a legitimate question of whether Carter remains the first choice.
The two obvious back-ups, who have performed impressively over the past two seasons, are Aaron Cruden and Beauden Barrett. Both have been forced to fill in for the No. 10 jersey and have shown themselves to be the equal of any other fly-half in the world.
Along with these two, Colin Slade is playing the best rugby of his career, Lima Sopoaga is maturing into a reliable kicker and playmaker, while Tom Taylor showed his worth in his one test outing last season.
But with this increase in depth, one must ask where this leaves Carter as the sun sets on what has been a fantastic career.
Certainly when he is on the field and at his best, none of these men come close to Carter. His all-round game is still a couple of notches above his competition, and it is this that has made him such a valuable asset over the years.
He is the only fly-half in New Zealand who can confidently steer a team around the park at international level. His in-field kicking is superb, capable both of kicking short for his chasers to compete for when it is on, but also kicking long and getting the ball to roll and turn around the defenders to allow his chasers to apply pressure when the opposition back three is standing too shallow.
Not only this, he has the ability to recognize when to do each, realizing that a successful kicking game is one that utilises the space available to manipulate the opposition defenders to create space elsewhere. This then allows an attack to be built.
His ability to sum a situation up quickly remains the best in the world too, recognizing when and where to kick, pass and run. He does a good job of recognizing holes and defensive mismatches, knowing when to take the line on, and his strength makes him so hard to bring down when he does decide to go.
Defensively he has the best technique of them all and goes looking for tackles to make, meaning the defensive line can be more flexible in how it organizes itself. This allows the forwards to spread out across the field more and can save an extra man having to get into position, thus meaning they stay fresher for longer.
The problem is, the frequency of when we see this Carter is becoming less and less. At the end of last year's Super Rugby competition, we saw just how good a player he still is, playing arguably as well as he has ever done.
But since then, he has been hampered by injury, making just six performances for the All Blacks, where he never really got his best game going. Having been sidelined for most of the latter part of 2013 and having taken a sabbatical for the first six months of this year, he will return having seen little rugby in the past year. Just how consistently he will be able to play at his best remains the integral question.
In the meantime, Cruden and Barrett have both taken giant steps in becoming what many would consider world class. Initially both raw prospects who could ignite a backline, both men have become more assured in their kicking games and are getting a better feel for directing the game.
One need only look at the way the Chiefs' Super Rugby season has imploded since losing Cruden to injury to see his value to a team. When it comes to putting men into space, there is none better. He will take the ball to the defence and run lines to ensure his outsides are receiving the pass so they are hitting a gap.
Defensively, he is much improved from two years ago, while his kicking game has come a long way too, as was seen in his masterclass against France in the second Test last June.
Barrett, on the other hand, has the best running game of the lot. He picks his moment well and is tough to haul in when he decides to go, as he has tremendous speed and a keen eye for a gap. Kicking-wise he is improving too and looks to be controlling the Hurricanes play far better than he did in 2013. Defensively he still has questions to answer, but he is increasingly looking better in this area, and as has been shown over the past few years, there are ways to hide weak defenders in this position.
While it will provide the selectors with comfort to see Slade, Sopoaga and Taylor in such good form too, the reality is they tend to pick by what they have done before, so it will likely be one of the first three who gets the nod.
It really comes down to how much of an impact you see Carter's injuries as having. Whether he can hold himself together for another year and a half remains a huge question and will influence how the situation pans out. If he can slot back into the No. 10 jersey and play the rugby we all know he can, then he no doubt is the best option. But it is not as easy as that, as it often takes a number of good performances to play yourself into form and get up to the speed and physicality that test rugby demands.
Cruden, although currently injured, is younger and consequently far less injury-plagued, meaning he can hold the position down with more consistency. This will allow combinations to develop and form to develop. Likewise with Barrett, who is pushing ever closer to the jersey and may well be the first-choice fly-half for the June Test series against England.
It is a good problem for the All Black selectors to have, after such a lean period between 2008 and 2011. Four years on from that fateful day of Carter's injury in 2011, it could be any of the three who leave New Zealand as the team's No. 1 fly-half for the 2015 Rugby World Cup. Barrett's running game may not flourish so much on the softer European grounds. However, his defensive game will also be less exposed. Cruden's ability to ignite his back line may be of less significance too but will still be vital in the All Blacks campaign.
A fit Carter would fit the bill perfectly. He has a year and a half to get himself back up to speed and to remain injury-free. Can he do it? That is the million dollar question and could be the most important one in determining the All Blacks' chances of a successful World Cup defence.