The All Blacks missed Carter's cultured left boot in Dunedin. They missed his ability to carve huge chunks of territory - form a left-foot-right-foot combination with Israel Dagg.
They missed Carter's navigational skills, his unhurried, unflappable poise on the ball.
Sometimes it is hard to even say what it is exactly Carter brings that others don't - but it just feels that the All Blacks are a better, more fluid, more exacting team when he's in the No 10 shirt.
It certainly feels like they need him, really need him to be fit to play both Argentina and South Africa. Those two games are shaping as the toughest of the season. The Pumas know they should have beaten Australia last night and that anger combined with being back at home...they'll be as much fun to handle as a hedgehog.
As for the Boks in Johannesburg, they'll play virtually no rugby and look to take the proverbial baseball bat to the All Blacks.
Blunt objects such as the Pumas and Springboks need to be firstly appeased and then calmly sliced with a touch of rapier - and that sort of job is still best trusted to Carter.
Cruden has been tenacious and brave in his last two tests. Wobbly starts have been put behind him and he's battled hard to stay involved. That's all well and good for his longer-term development but the All Blacks need Carter in two of the more hostile venues they will encounter.
All Black coach Steve Hansen says he's hopeful that the squad's most experience first-five will be declared fit and be on the plane to Buenos Aires and that if he is, its likely the selectors will travel with the original 28 picked for the Rugby Championship.
If there are doubts over Carter, then possibly Beauden Barrett will travel and one of the props or loose forwards will be left behind.