Pat Cummins and Josh Hazlewood have both been rotated out for this morning's (Saturday evening local time) contest with Scotland in Saint Lucia, where Mitch Marsh won the toss and opted to bowl first.
But it is the inclusion of Agar over allrounder Cameron Green that reveals how Australia are planning to tackle what will likely be three Asian opponents in the Super Eights stage from next week.
Agar could also come into calculations to face Afghanistan in Antigua and then India in their final Super Eights match back in St Lucia.
But the strength of their middle-order and the other allrounders is keeping him (as well as wicketkeeper-batter Josh Inglis) on the sidelines.
And if he does need to come in, his work in the IPL will hold him in good stead."
Australia makes two changes for crucial catch that will determine who progresses from Group B to the Super Eight stage
Ashton Agar has been blooded for his first game of the T20 World Cup with a view to the left-arm spinner playing an integral role in the next stage of Australia's Caribbean campaign.
Pat Cummins and Josh Hazlewood have both been rotated out for this morning's (Saturday evening local time) contest with Scotland in Saint Lucia, where Mitch Marsh won the toss and opted to bowl first.
Mitchell Starc has recovered from a calf niggle to feature alongside Nathan Ellis in a match that has no ramifications for the already-qualified Aussies, though the Scots need a win to make it through at England's expense.
But it is the inclusion of Agar over allrounder Cameron Green that reveals how Australia are planning to tackle what will likely be three Asian opponents in the Super Eights stage from next week.
Agar has played just three international matches over the past 18 months and it has been nearly two years since he pulled on an Australian shirt for a T20, due to injury and Adam Zampa's hold on the frontline spin-bowling spot.
Yet the 30-year-old looks set to be thrown into the fire at the expense of one of the big three pacemen for at least one of Australia's three second-round matches that will determine whether they can become T20 champions for a second time.
Their second Super Eights match (most likely against Bangladesh) in Saint Vincent, where spin has captured 19 of the 27 wickets to fall in the venue's two games so far this tournament, has been identified as one match that will necessitate Agar's inclusion alongside Zampa.
Agar could also come into calculations to face Afghanistan in Antigua and then India in their final Super Eights match back in St Lucia. Surfaces on those islands have been less spin-friendly but that could change as wicket tables get worn down by multiple games over coming days.
Selection chief George Bailey revealed their internal analysis showed "the ball was spinning between 5-7 (degrees) off the middle of the wicket" at the Arnos Vale ground in St Vincent.
"Deep in a tournament, when the same grounds are being used a lot, we're starting to see some wickets that are starting to show a bit of fatigue in the West Indies.
"A lot of the guys we've got in the group have got a bunch of cricket behind them, either through the IPL most recently or have played quite a bit in this team.
"But Ash, just coming off his injuries and the way we've structured up when he has been available, he just hasn't been able to get much game time, as much as he'd probably like.
"He's training really well, as is everyone, but just getting that opportunity in the middle to be able to put that into place, for Mitch (Marsh) to be able to navigate what it's like with a number of spinners in the team.
"Every ground we've been there’s been a decent breeze, and potentially a short (boundary) and potentially how he navigates that and how he utilises the other bowlers and how he incorporates Ash into the bowling group (will be beneficial)."
Green finished his IPL campaign at Royal Challengers Bengaluru in style, adjusting to a role in the middle-order while also shining with the ball, and has spent more time in the nets than any of the Australians during this World Cup.
But the strength of their middle-order and the other allrounders is keeping him (as well as wicketkeeper-batter Josh Inglis) on the sidelines.
Marcus Stoinis has been arguably Australia's best player so far and is the most similar type of player to Green among the incumbents, while Marsh looks set to be available to bowl when the Super Eights begin following a hamstring injury.
Bailey believes Green will be able to draw on his strong IPL form if he is required, potentially in an eight-batter line-up Australia have flirted with using on the right type of surface.
"He’s got a really good run in the IPL. I think his game is in a really good place," said Bailey.
"Potentially in an ideal world you’d love to get the balance of being able to give everyone a game but you do need to offset that with making sure you give the guys that are playing the prep that they need and the opportunity to be able to keep their rhythm and continuity.
"We talked about, 'let’s see if we can give Greeny a game', but we are really confident that he’s in a good place. And if he does need to come in, his work in the IPL will hold him in good stead."
Australia XI: David Warner, Travis Head, Mitch Marsh (c), Glenn Maxwell, Marcus Stoinis, Tim David, Matthew Wade (wk), Ashton Agar, Mitch Starc, Nathan Ellis, Adam Zampa Scotland XI: George Munsey, Michael Jones, Brandon McMullen, Richie Berrington (c), Matthew Cross, Michael Leask, Chris Greaves, Mark Watt, Chris Sole, Brad Wheal, Safyaan Sharif
2024 ICC Men's T20 World Cup
Australia's squad: Mitch Marsh (c), Ashton Agar, Pat Cummins, Tim David, Nathan Ellis, Cameron Green, Josh Hazlewood, Travis Head, Josh Inglis, Glenn Maxwell, Mitchell Starc, Marcus Stoinis, Matthew Wade, David Warner, Adam Zampa
Australia's Group B fixtures
June 6: Beat Oman by 39 runs
June 9: Beat England by 36 runs
June 12: Beat Namibia by nine wickets
June 16: v Scotland, Daren Sammy Stadium, St Lucia, 10.30am AEST
Australia's Super Eight fixtures
21 June: v D2, Sir Vivian Richards Stadium, Antigua, 10.30am AEST
23 June: v Afghanistan, Arnos Vale Ground, St Vincent, 10.30am AEST
25 June: v India, Daren Sammy National Cricket Stadium, St Lucia, 12.30am AEST
Semi-finals to follow if Australia qualify
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