Despite being named to lead Australia's World Cup campaign, Michael Clarke faces another battle against the calendar to prove that he is fit and ready to be part of the ICC's showpiece event that begins in less than five weeks.
Clarke will captain Australia's 15-man squad but has been told by chair of the National Selection Panel, Rod Marsh, that if he's not able to play in the team's second match of the event – against Bangladesh in Brisbane on February 21 – he will be ruled out of the tournament.
That means the 33-year-old will need to fast-track his recovery from the surgery he underwent on December 16 to stitch the hamstring tendon at the top of his right leg and which team medical officials believed would sideline him for up to 10 weeks – until the end of February.
The uncertainty surrounding the likelihood of Clarke's involvement in the six-week tournament was the major talking point of today's announcement.
The inclusion of young seamer Josh Hazlewood ahead of veteran Ryan Harris prompted some debate, as did the choice of left-arm tweaker Xavier Doherty as the squad's sole specialist spinner.
Despite Steve Smith's installation as Test captain while Clarke was injured, George Bailey has been retained as vice-captain of the ODI side and will lead the team in the upcoming Carlton Mid ODI Tri-Series against England and India.
And in the World Cup until – indeed if – Clarke proves his fitness.
Clarke is still Australia's preferred on-field leader // Getty Images
These decisions were all explained at length by Marsh who sat alongside Clarke to answer questions about the line-up and the rationale behind the February 21 deadline – by which time Australia will finalise their squad barring any late mishaps – imposed on the skipper.
Clarke had already indicated he would not be available for Australia's marquee World Cup opener against England at the MCG on February 14 and it is understood medical opinion had him eyeing the team's fourth of their six pool games against Afghanistan in Perth on March 4.
But in imposing the February 21 cut-off for Clarke – and for any other member of the squad who might be struggling with injuries in order to ensure a settled line-up for the second half of the World Cup campaign – the selectors have drawn a clear line in the sand.
If Clarke is at odds with the National Selection Panel over that edict, he gave little away during today's media event at a harbourside location in Sydney.
"I've obviously got my work cut out," Clarke said when asked about his chances of being passed fit to bat, bowl and field without restriction by February 21 and as to why he had already identified the tournament opener as being too early for his return.
"It's more than a gut feeling, it's much more than that. It's advice from the surgeon, from the Australian medical staff in regards to the time frame after having my surgery up until the Bangladesh game, which is about nine and half weeks post my surgery.
Quick Single: Hamstring woes no worries for Mitch Marsh
"The experts believe I'm going to need every bit of that nine and half weeks to give myself every chance (but) it won't be a lack of work that doesn't get me there, that's for sure.
"I'm confident I'll be fit. I'm sure there will be (fitness) tests along the way, my goal is to pass every single one of those and when that happens I'll be fit to walk out.
"The Australian medical staff will make the decision that I'm okay to walk out on that park and perform at my best so it's really irrelevant what I think to be honest.
"That's what they've gone with, the selectors. That's the system."
Quick Single: Clarke targets 'majority' of World Cup
While Clarke has already effectively ruled himself out of the February 14 match against England, Marsh indicated the skipper might be a chance to play in Australia's final pre-tournament warm-up game against the United Arab Emirates at the MCG on February 11.
And while he jokingly suggested Clarke might be restricted to hitting boundaries in that fixture – to which Clarke laughingly interjected he would hopefully be running by that stage – Marsh put the onus on the captain as well as the Australia Bupa Support Team medical staff to make a final diagnosis.
"He (Clarke) knows what he's got to do," Marsh said.
"He's played enough cricket to know when he's right to play. It would be really nice if Michael could go and play some cricket before the 21st (of February).
"In an ideal world it would have been nice to have Michael ready for the first game, in an ideal world it'd be nice to have all 15 ready for the first game, but that's not going to be the case.
"So we had to draw the line somewhere, we just couldn't keep it hanging on and on and on. That (February 21) is where we drew the line and that's what we decided."
Quick Single: Harris held back with eye on Ashes
Marsh confirmed that the decision to overlook Harris was made because of the 35-year-old's advancing years and his recent history of injuries that would make it difficult for him to push through the hectic World Cup schedule.
As a result, Marsh declared the highly valued seamer's days at one-day international level are formally at an end and that he would be nursed through to this year's five-Test Ashes campaign which begins in June.
Harris last played an ODI in early 2012 // Getty Images
"We would really like to see Ryan go to England, bowl his heart out in Test cricket and keep those Ashes," Marsh said.
"He's that important to the team in Test match cricket.
"I know there's nothing bigger than the World Cup but maybe international one-day cricket he's had his time there."
Marsh explained that the selection of Doherty ahead of incumbent Test spinner Nathan Lyon (leading wicket-taker in the recent Commonwealth Bank Series against India) and promising leg spinners Cameron Boyce and Adam Zampa was a pragmatic one.
Quick Single: Maxwell backed to make all-round impact
With all-rounder Glenn Maxwell (Australia's second-highest ODI wicket-taker for the past year behind James Faulkner) providing an off-spin option and Smith able to offer wrist spin when needed, Doherty's proven ability to land his left-arm orthodox tweakers rounded out the set.
Especially with doubts over how many overs of his left-armers Clarke might be able to produce.
"Xavier is a proven one-day bowler," Marsh said.
"We know exactly what we're going to get with Xavier.
"It's a little bit different these days because there's only four men outside the circle (due to new fielding restrictions) and it makes it a little bit more difficult I think for some spinners, and I'll leave it at that."
Smith won't have captaincy worries in the World Cup // Getty Images
When asked if consideration was given to handing Smith the ODI vice captaincy in keeping with his elevation in the Test set-up, Marsh claimed the 25-year was feeling the pinch of his three-Test stint as skipper and that Bailey had performed the role admirably in Clarke's earlier absences.
"George has done a fantastic job with the team and you know what, after Steven playing three Test matches leading Australia in Test cricket, I think he's pretty tired and I think he'll relish the fact he can just go out there and play cricket," Marsh said.
Quick Single: Bailey draws strength from strong leadership
"George is an experienced campaigner in one day cricket captaincy and we thought that's probably the way to go.
"We don't want to make it too hard on Steven just at this point in time because he's in such a rich vein of form."
The 15-man World Cup complement will be the same squad used for the Carlton Mid Tri-Series that begins on Friday when Australia tackles England at the SCG, but with a couple of additional pace bowlers to be added to the touring party as cover.
Given the heavy workloads undertaken by Mitchell Starc and Josh Hazlewood during the fourth Test, and the hamstring problems recently suffered by Perth-based pair Mitchell Johnson and Mitchell Marsh, the selectors have named South Australia’s Kane Richardson and New South Wales seamer Gurinder Sandhu as extra bowling options for the early matches of the Tri-Series.
Clarke will also travel with the ODI squad throughout the Tri-Series even though he won’t be available to play, in order to maintain his daily rehabilitation program under the guidance of Bupa Support Team physiotherapist Alex Kountouris.
Australia's Cricket World Cup squad: Michael Clarke (c), George Bailey (vc), Pat Cummins, Xavier Doherty, James Faulkner, Aaron Finch, Brad Haddin, Josh Hazlewood, Mitchell Johnson, Mitchell Marsh, Glenn Maxwell, Steve Smith, Mitchell Starc, David Warner, Shane Watson.
Australia’s World Cup Fixtures
February 14: v England, 2:30pm at the MCG
February 21: v Bangladesh, 1:30pm at the Gabba
February 28: v New Zealand, 2:00pm at Eden Park (NZ)
March 4: v Afghanistan, 2:30pm at the WACA
March 8: v Sri Lanka, 2:30pm at the SCG
March 13: v Scotland, 2:30pm at Blundstone Arena
Remember, you can also support Australia on the road to the World Cup by either tweeting @CricketAus the hashtag #CmonAussie or visiting this page to get your digital autograph from Clarke and go on to purchase your very own personalised World Cup top.