And once he's back, it won't quite be the last chance saloon, but he is going to have to show something of his former self to win his All Black place. It's not like the old days where he could hop about on one leg and still be the All Blacks' preferred choice at first five.
There is real competition from players who are maybe not as gifted, but are certainly gifted enough.
The selectors remain confident Carter can still be a world-class operator: maybe not the player he was in his prime, but the best No10 in the country and certainly good enough to steer the All Blacks in the World Cup.
His focus, his drive, his ambition are all there. He's hungry - he's eager to prove himself and sign off in style before he heads to France.
So what has to happen for Carter to start being Carter again?
The All Blacks talk of the game being essentially run, pass, catch. Carter has become more catch, pass, run. He's fallen into the trap of seeing his role as being almost exclusively about organising others.
He's been taking his directorial duties a little too far. He sees the game more clearly than most. He can feel the space on the field, instinctively know the right play and he's got the confidence and authority to boss those outside him.
Those skills form a big part of any No10's brief - but Carter, in his prime, offered so much more than that. Aaron Cruden offers more than that. Beauden Barrett does, too, and so does Colin Slade, and that's the challenge for Carter, he's got to shake free from this conviction that he's there exclusively to play others into the game.
It was Carter's running game that so famously tore the Lions apart in 2005. It was Carter's running game that was top drawer throughout 2008 and his running game that he considers the key to his confidence.
When he runs well, he plays well - it's that simple. But when was the last time Carter tormented a defence with his change of pace and thrust?
When did he last look effortless in the carry, dancing and dodging - making holes and taking holes? The answer is, against Scotland in 2012.
When Carter returns, maybe he must tell himself to forget all he knows and spend the first 20 minutes hurtling at the line.
He's spent a career being selfless, but a little bit of selfishness wouldn't do him any harm over the next month.
Patrick McKendry
Israel Dagg, a man who has his own point to prove this season, could hold the key to Dan Carter's return to the Crusaders.
Like Carter, Dagg has been left out of the team to play the Chiefs at Waikato Stadium because of a leg injury. Unlike Carter, he looked sharp and dangerous before he was forced to limp off, in his case in the 26-20 victory over the Highlanders in Dunedin last weekend.
On the form he showed under the southern roof, Dagg is a shoo-in for selection if he recovers in time to play the Lions after next weekend's bye. It is clear he is a much better fullback than Tom Taylor, who will play in the No15 jersey against the Chiefs.
However, Colin Slade is also an excellent fullback - brave under the high ball and as a defender, and a brilliant counter-attacker.
If Dagg is unavailable, the Crusaders wouldn't lose much by moving Slade to the back and reinstating Carter to No10, his best position, once he recovers from an injury understood to be a jarring of the bone he broke in last year's Super Rugby final. But if Dagg is at fullback, the Crusaders will be wary about removing an in-form Slade from first-five.
What will probably occur is a compromise which they went with last season. In that arrangement, Carter will play at second-five outside Slade, with Ryan Crotty at centre. That formation, with Andy Ellis at halfback and Nemani Nadolo on one wing and either Johnny McNicholl or Robbie Fruean on the other, would be a formidable backline; a mix of speed, guile and blockbusting power.
It is a combination the Crusaders stumbled on following Carter's return from his Achilles problem last year late in the round-robin and it brought a fair amount of success until the 32-year-old's bad luck in the final.
In other words, Slade must be considered the incumbent No10 at the Crusaders now, but Carter will still have a big part to play at second-five, and injuries could move him closer to the action.
Those close to the Crusaders believe he is looking forward to the challenge, that he is physically and mentally able to fix those flaws which dogged his game in round one against the Rebels. Forget about the All Blacks, Carter's fight right now is to get fit enough for a return and once he is there put pressure on Slade for that red and black No10 jersey. It might just bring the best out of him.
