Usman Khawaja could learn his Boxing Day fate as early as Friday when he undergoes a fitness test on his injured hamstring that will also have ramifications for incumbent duo Shaun Marsh and Joe Burns.
The stylish left-hander will spend his 29th birthday being put through his paces under the watch of Sydney Thunder physio Murray Ryan in a bid to prove his fitness for Sunday's Big Bash League clash with the Melbourne Stars at the MCG.
While the second Test is still more than a week away, Friday is effectively D-Day for Khawaja if he wants to return in Melbourne. Cricket Australia's medical staff will make the final call over Khawaja's Big Bash availability. 
Although Twenty20 is derided by some as hit-and-giggle cricket, players say the shortest of the game is actually the most physically taxing due to the tempo at which it is played.
Khawaja has not played since tearing his hamstring while fielding in the Perth Test a month ago and selectors want to see if he can handle the heat of a competitive match before they pick him.
"Usman's first got to be fit. If he's not fit he won't play, there's no doubt about that," coach and selector Darren Lehmann said this week. "We've got to make sure he's playing BBL to get some sort of match fitness and see how the strain of the hamstring is and then when we get him in on the 23rd [  December] we'll have a look and see whether he's available to play."
Khawaja is believed to have been very close to playing in Thursday night's Sydney Smash but CA decided to err on the side of caution with the Test No.3. But Khawaja's Test summer will not be over even if he is ruled out for Melbourne. The Thunder play again on   December 28, giving him another chance to test his hamstring before the Sydney Test the following week.
His availability is a key piece in Australia's selection puzzle.
Selector Mark Waugh has said Khawaja's hot form, which includes centuries in Brisbane and Perth, demanded an automatic recall if fit, but Rod Marsh's panel will be spared a major dilemma if he comes up short. Marsh and Burns both have reason to be sweating on the outcome as their place in the XI will come under threat if Khawaja is fit.
Opinion is divided over which player should make way as both have performed well in the baggy green. Burns is averaging 41 opening the batting this season though his form has tailed off since making his maiden Test ton in Brisbane.
The frequency at which he has been bowled will also be a concern for selectors, who do not like seeing batsmen dismissed in similar fashion. Should he be omitted, Khawaja would be thrust into the new role of opener, breaking up the fruitful partnership Burns has enjoyed with David Warner.
If Marsh was to be dropped Khawaja would slot back into first drop with captain Steve Smith moving back to No.4.
Whichever way selectors lean, it is unlikely to have much bearing on the outcome in Melbourne as Australia are expected to comfortably beat the hapless West Indies.
But selectors will want to give their first-choice top six every opportunity to gel before the Test tour of New Zealand, who are expected to provide much stiffer opposition at home than they did on this side of the Tasman last month.