A sore back restricted Steve Smith to spectating duties at Australia's first training session at the SCG but the skipper is considered in no doubt for the fifth Magellan Ashes Test.
Smith is renowned for his marathon net sessions and being the first to arrive at training and the last to leave.
The world's best batsman didn't hit a single delivery on Tuesday, instead casting an eye on teammates while chewing the fat with coach Darren Lehmann and chairman of selectors Trevor Hohns.
Smith, who also sat out slips practice, is expected to have a hit on Wednesday.
The skipper could be excused for having a stiff back after spending more than 31 hours at the crease against England in this series, becoming Australia's first captain to score 600 or more runs in an Ashes campaign since Don Bradman.
"Even for him, there is only so many balls his body can take hitting in a week. I'm sure he'll make up for it tomorrow," Pat Cummins said.
"He'll probably be here all day I'm guessing."
Former England skipper Michael Vaughan joked on Twitter that Smith's sore back was "no surprise with the amount he carries this team".
Much of the intrigue around the series finale, which starts at the SCG on Thursday, centres on how many more records Smith can break.
He is currently averaging 151 in this series, the best ever rate by a batsman in an Ashes series to have batted in more than two innings, beating Geoffrey Boycott's mark of 147 in 1977.
The 604 runs Smith has scored the fourth-most by a captain in an Ashes series, with the 810 Bradman scored in 1936-37 the high mark. Another century in Sydney see him join Bradman, Herbert Sutcliffe and Wally Hammond as the only men to score four hundreds in the same Ashes series.
Mitch Marsh rates Smith's leadership highly, saying the skipper inspires with words as much as he does the willow.
"He's in incredible form but the thing I love most is the way he leads," Marsh told reporters in Sydney.
"You want your captain to be leading on the field and off it. The way he does it all is unbelievable.
"He loves the game. It's just his hunger for us to be a successful team ... it's rubbing off on all of us.
"We've all got so much respect for him and hopefully his form continues."
Marsh was at the non-striker's end for much of Smith's career-best knock of 239 in Perth then formed another key partnership with his skipper in Melbourne, ensuring Australia salvaged a draw.
"The other day it was like he was having a net session," he said.
2017-18 International Fixtures
Magellan Ashes Series
Australia Test squad: Steve Smith (c), David Warner (vc), Cameron Bancroft, Usman Khawaja, Peter Handscomb, Shaun Marsh, Mitchell Marsh, Tim Paine (wk), Mitchell Starc, Pat Cummins, Nathan Lyon, Josh Hazlewood, Jackson Bird, Ashton Agar.
England Test squad: Joe Root (c), James Anderson (vc), Moeen Ali, Jonny Bairstow, Jake Ball, Gary Ballance, Stuart Broad, Alastair Cook, Mason Crane, Tom Curran, Ben Foakes, Dawid Malan, Craig Overton, Ben Stokes, Mark Stoneman, James Vince, Chris Woakes.
First Test Australia won by 10 wickets. Scorecard
Second Test Australia won by 120 runs (Day-Night). Scorecard
Third Test Australia won by an innings and 41 runs. Scorecard
Fourth Test MCG, drawn. Scorecard
Fifth Test SCG, January 4-8 (Pink Test). Tickets
Gillette ODI Series v England
First ODI MCG, January 14. Tickets
Second ODI Gabba, January 19. Tickets
Third ODI SCG, January 21. Tickets
Fourth ODI Adelaide Oval, January 26. Tickets
Fifth ODI Perth Stadium, January 28. Tickets
Prime Minister's XI
PM's XI v England Manuka Oval, February 2. Tickets
Gillette T20 trans-Tasman Tri-Series
First T20I Australia v NZ, SCG, February 3. Tickets
Second T20I – Australia v England, Blundstone Arena, February 7. Tickets
Third T20I – Australia v England, MCG, February 10. Tickets
Fourth T20I – NZ v England, Wellington, February 14
Fifth T20I – NZ v Australia, Eden Park, February 16
Sixth T20I – NZ v England, Seddon Park, February 18
Final – TBC, Eden Park, February 21