Three years later, the allrounder is on the verge of the most unlikely recall after landing back in Australia's squad for the home multi-format series against India.
Fearing her cricket had "plateaued" after years as a reserve and fringe player in Australian squads, Carey made the bold call to prioritise pre-seasons at home.
Carey said she "made peace" with the thought her decision might have meant she would never play for Australia again.
"If you'd asked me, I would have said, 'It's really unlikely it would happen again'," she said ahead of Sunday night's series-opening T20 at the SCG.
"It was just about playing more games of cricket, and that was just the path I thought was the best way to go about it for me.
"I didn't really have any goals or expectations of where that would get to in terms of making this team again."
Carey was as surprised as anyone to be called by chief selector Shawn Flegler last month.
She will return a far more complete cricketer, adding new-ball bowling to her repertoire and having refined her T20 batting.
The result has been player-of-the-final honours in last year's Hundred in England, before being crowned Australia's best domestic player on Thursday with Tasmania.
"When you're on tour, it's a lot of top-up training," Carey said of her time in Australian sides.
"It's 'get what you need to be ready for the game'. And if you're not playing in those games, it's harder to get that time in the nets.
"It makes complete sense. The priority is the playing 11. You're on tour, or in tournament.
"But then I used to find it really tricky coming back to Big Bash.
"You'd come back as the Australia player, you're meant to lead the way. But I always felt quite underdone."
Carey has also admitted time on the sideline had meant her love of cricket took a hit.
But at age 32, she required no convincing to return to an Australian team looking to win back the ODI and T20 World Cup trophies.
And nor does she worry about the possibility of more time on the road, with a tour of the Caribbean and the T20 World Cup in England in the next five months.
"I was an OK player. But I probably didn't know my game that well. I definitely needed to work on a heap of things," Carey said.
"Now I'm in a place where I've been able to do that. You get a bit older, I've got a few years under my belt now.
"I feel like I've got enough now where I can tinker as you go and work on things."