Solving the sixth bowler puzzle in Australia's ODI XI is the biggest test facing Matthew Mott and the selection panel ahead of the opening Commonwealth Bank Women's Ashes match on Sunday.
Australia were found out in this winter's World Cup in the UK with only five recognised bowling options in the playing XI, unable to right the ship if a frontline bowler was off their game.
The absence of a genuine sixth bowling option was never more felt than in the semi-final loss to India when Harmanpreet Kaur compiled an out-of-this-world 171no to which the Australians had no answer.
Part-timer Elyse Villani was used in the tournament as the sixth bowler when required, and while she did her job admirably, Mott now wants a more accomplished bowler in the starting side to fall back on.
"That's one of the big things we identified that we needed to improve on," Mott told The Unplayable Podcast.
"We had some options there (at the World Cup) and they didn't quite come off, I think a couple of innings showed that up.
"Our plans were pretty good for the majority of the time but a couple of times when it didn't go well it went really badly.
"I think we need that sixth bowling option and that's probably why it's going to be the hardest decision in terms of our team balance."
Squeezing in another bowler into Australia's star-studded XI will be no easy feat, and it looks as though it may come at the cost of one of the two wicketkeepers in the top seven.
Alyssa Healy has been Australia's 'keeper since the retirement of former captain Jodie Fields three years ago, while opening batter Beth Mooney stands behind the stumps for Queensland at domestic level.
Healy's ODI average of 15.96 belies her ability with the bat, which was damaging coming in late during the World Cup to put the finishing touches on an innings.
Her 63no from only 47 balls against Pakistan at Leicester represents not only her highest score for Australia but her destructive ability when firing on all cylinders.
Healy is also one of the most experienced players in the squad and was present in 2015 when Australia won the Ashes in England with a match to spare.
At the other end of the order is Mooney, who has built a solid opening partnership with Nicole Bolton.
Together the pair have put on two century stands at an average of 43 in 16 innings, while Mooney has a top score of 100 to go with five half-centuries in 17 matches.
In Tuesday's practice match against the Cricket Australia XI, Healy donned the gloves for 25 overs before swapping with Mooney, who got through only six overs when heavy rain stopped the match for good.
Waiting to come into the XI is allrounder Tahlia McGrath and seamer Lauren Cheatle, but both youngsters are finding their groove having spent much of the winter sidelined with injury and only just returning to competitive bowling last weekend in the Women's National Cricket League.
Whichever way the selectors go, and it could be that both Healy and Mooney feature at Allan Border Field on Sunday, Mott knows the gravity of the decision that must be made.
"That's the big question at the moment," Mott said when asked if both Healy and Mooney can exist in the same side.
"Take their wicketkeeping aside they're definitely some of Australia's best batters.
"The fact they're wicketkeepers is a bonus in many ways.
"They're both outstanding players, both done very different roles for us over the last year or so.
"Alyssa Healy has been excellent at providing that punch at the back end of the innings. She struck at 150 (runs per hundred balls faced) during the World Cup and executed the role that we asked her to do really well.
"Beth's last 18 months have been really good. She's got us off to solid starts a lot and the game that we play is about getting a big base to start with and trying to come home, like most of the teams in the world.
"I think they both can exist in the same side but that's one of the selection dramas we'll have over the next couple of days about getting our top six batters right.
"There's still a couple of opportunities for players to put their hands up."
Commonwealth Bank Women's Ashes
Australia squad (ODI and Test): Rachael Haynes (C), Alex Blackwell (VC), Kristen Beams, Nicole Bolton, Lauren Cheatle, Ashleigh Gardner, Alyssa Healy, Jess Jonassen, Tahlia McGrath, Beth Mooney, Ellyse Perry, Megan Schutt, Belinda Vakarewa (Test only), Elyse Villani, Amanda-Jade Wellington.
England squad: Heather Knight (c), Tammy Beaumont, Katherine Brunt, Sophie Ecclestone, Georgia Elwiss, Jenny Gunn, Alex Hartley, Danielle Hazell, Laura Marsh, Anya Shrubsole, Sarah Taylor, Nat Sciver, Fran Wilson, Lauren Winfield, Danielle Wyatt.
First ODI Allan Border Field, October 22
Brisbane Charity Partner: Lord Mayor's Charitable Trust
Second ODI Coffs International Stadium, October 26
Third ODI Coffs International Stadium, October 29
Day-Night Test North Sydney Oval, November 9-12
First T20 North Sydney Oval, November 17
North Sydney Charity Partner: McGrath Foundation
Second T20 Manuka Oval, November 19
Third T20 Manuka Oval, November 21
Canberra Charity Partner: Lord's Taverners ACT