Agar suffered a minor calf tear in an innocuous incident while training with Western Australia during the pre-season which ruled him out of the T20I portion of the South Africa. But he will be in contention for the ODI series, which starts late next week, and will fly to South Africa on Thursday alongside Cameron Green, David Warner, Josh Hazlewood and coach Andrew McDonald who have all been rested from the T20Is ahead of the one-dayers which lead into the World Cup.

Speaking at the launch of the BBL overseas draft on Wednesday in Melbourne, where Agar was hopeful Perth Scorchers could retain some of the previous players that had helped them win the last two titles, he was frustrated to have suffered another setback, having injured his side twice on overseas tours in 2022. But he was confident he will be ready for the start of the ODI series next Thursday.

"It was really unfortunate," Agar told ESPNcricinfo. "I was going really well in the pre-season and my body was in a really good place. Feeling very fit. And unfortunately got a little tear in that calf. But it's been a really good rehab. We've got great physios on staff [in WA] and have been working really closely every day with them. I've done a couple of full-intensity sessions at the WACA now. So I think I'll be up to playing at 100% intensity in an ODI."

Agar faces a similarly compromised preparation coming off his calf injury. He is also expecting the birth of his first child and is set to fly home from South Africa late in the five-match ODI series before rejoining the squad in India.

Agar's World Cup role will depend on Australia's balance

He has not played in an ODI World Cup but will be a key man in Australia's campaign as they are set to play with differently structured sides throughout the tournament depending on the conditions and the fitness of the squad. They will play nine round-robin games in eight different cities in just over a month.

Australia's selectors showed their cards in the recent series in India in March where they played three different line-ups, all of which they might use in the World Cup. They have trialed playing eight batters, including four allrounders, and just three specialist bowlers. They have also played with seven batters, three quicks and one spinner with Zampa playing as the lone specialist and Maxwell providing spin support.

Australia's opening World Cup game is against India in Chennai on October 8 and Agar is eager to play a role.

"World Cups bring out the best in one-day cricket, particularly in India," Agar said. "You never know what pitch you're going to get. But the chances are as a spinner that you'll be playing, and there's a chance that you play two spinners in a lot of the games, particularly if the pitches get tired.

"It's a place I love going. I've had really great experiences. Obviously, the Test tour was a difficult experience there. But then I got to go back and play that one-dayer and do really well. It's a place I really like to bowl."

Agar's India Test series: 'That was my chance and it didn't happen'

"It's never easy," he said. "You probably take a hit to your pride more than anything. Even after Sydney. All I'm trying to do is my best every single time. I'm always trying to get better. That's just who I am. And I give as much as I can to any team that I play in. But I felt okay coming back from India because I tried my arse off. It wasn't where it needed to be.

"It was wonderful communication [with the selectors] and a clear path forward. I think that's all you want. Yeah, I was flat. I had grown up wanting to play Tests in India forever. I think that's the coolest thing ever. And that was my chance and it didn't happen. So that hurt for sure.

"But there's no way I'm going to stand here and point fingers. Absolutely no way. It's just about moving forward. So I'm really strong on that attitude. And it's helped me bounce back all the time from little selection hiccups here and there and come back and ultimately try and perform."

Agar still wants to be a three-format spinner but is acutely aware of how difficult it is to switch between formats without long lead-ins.

"If we're talking about really trying to gear up for red-ball cricket it's as hard as it gets, especially as a spinner," Agar said. "[In limited overs] you're bowling six different bowls an over. Whereas a [Test] spinner in Australia, you need to bowl hard overspun balls and hit the same length, every ball. If you're not doing that for a long time, it's pretty hard to put that all together all of a sudden. It's really tough.

"But I've never wanted to be a one-dimensional cricketer. I want to be as selectable as possible. And I've always wanted to be a batter. I've always wanted to be a bowler and a good fielder. And it means that you can't invest all your time into one discipline. And you get spread a bit thin sometimes. But that's cool because I'm playing the game the way I like to play it. It's much more fun for me that way."