At that stage, Carey was nearing 26 and had played 20 games of professional cricket. To go from there to vice-captain, wicketkeeper and middle order saviour shows how little Australia had planned for this event.
Carey is not even a middle order player. He came to prominence after a pro Australian Rules football career by opening the batting for Adelaide Strikers. His South Australia record with red and white ball is fine, but not international worthy. It was the long innings opening the batting for the Strikers that made people take notice.
Until this tournament, he wasn't a success. He made some runs, but at a strike rate of 82, it was often too slow for someone coming down the order. This tournament he's averaged 41 in the five games so far, with a strike rate of 108, and he was run out in one game. There seems to be a touch of luck in Carey's sudden rise, but the talent he has is evident.
"All the other top contenders look like they know their best squads and elevens. Australia just turned up."
But Australia have used four wicketkeepers since the Champions Trophy, Peter Handscomb for one game, Tim Paine for a while and it was Matthew Wade who kept against Bangladesh last time. Wade's now in better Big Bash form than Carey showed to get his call up and is back with Australia A.
Moises Henriques was the seam-bowling allrounder in that last Bangladesh match. He has not played since that Champions Trophy. Since then Australia have tried James Faulkner, Michael Neser, and Mitchell Marsh. The role is now with Marcus Stoinis.
Travis Head bowled eight overs against Bangladesh in that last game; he hasn't played an ODI this year after a disappointing run in 2018. The Ashtons (Turner and Agar) have both been in as spin-bowling allrounders, though Turner didn't bowl. D'Arcy Short has bowled since then too, but it appears Glenn Maxwell is now the spinning allrounder (with help from Aaron Finch).
And there is Josh Hazlewood, the oddest omission. According to Cricket Australia's website, "Cup absentee Hazlewood set to 'explode'" is in the UK and fit enough for Australia A. Since the Champions Trophy, he's played in six ODI games, and he's now Australia's seventh-best one-day seamer according to the selections of Mitchell Starc, Pat Cummins, Nathan Coulter-Nile, Jason Behrendorff and the Richardsons Kane and Jhye. His economy rate in those six matches was 4.98.
Since the last World Cup, Hazlewood has played 31 ODIs, averaging 26 and conceding only 4.85 runs an over.
There are a few reasons he isn't here; injury is the main one and looking to the Ashes is perhaps another. But they could have brought Hazlewood in when Jhye Richardson wasn't fit. Instead, they were cautious with Hazlewood and went with Kane Richardson as a death-overs specialist. Since the last World Cup, Hazlewood has bowled 277 death-overs deliveries at less than a run a ball.
Since that Champions trophy, Australia have tried the knuckleballs of Andrew Tye, the scariness of Billy Stanlake and even old faithful Peter Siddle. And yet, even with all those options, Australia have barely used four frontline fast bowlers in a game. The first time they did, they took seven wickets against England and in the second their batsmen went in first and failed.
How is it possible that they haven't tried to use their main strength as a tactic in ODI cricket coming into the World Cup?
You could take it further, in Finch, David Warner, Steven Smith, Starc and Cummins, they have five fun players. They could have tried line-ups that included a solid top four, and then allrounders and hitters like Head, Maxwell, Turner (if bowling fit), Agar, Stoinis, Mitchell Marsh, Cameron Boyce, Dan Christian, Neser, Coulter-Nile filling spots five to nine, with Cummins and Starc. That would give them 11 batting options so that they could go hard, with two of the best seamers in the world still in their line-up.
That is all experimental, and it might have failed spectacularly, but what is the point of bilateral ODIs other than as cash cows and for experiments. And Australia have spent most of the last couple of years losing ODIs anyway.
When they have experimented, it's been with players, not tactics.
Australia have tried 33 players since the Champions Trophy, but no one has been used for more than 33 games. England have played 25, and six over 40. India have used 30 players, and seven over 40 (and two over 50). New Zealand played only 22 players in that time. All the other top contenders look like they know their best squads and elevens. Australia just turned up.
This tournament, they have a batting order full of top-order players out of position, forcing Usman Khawaja to make runs in a place he's never succeeded for Australia, using Shaun Marsh as a death-overs hitter. Finch has had to bowl, Stoinis has had to bowl at the death, and Hazlewood is preparing to bowl in an A game.
Of all the gambles they've made, only Carey has worked.