Travis Head will play in the Boxing Day Test, proving his fitness in a Christmas morning fitness test at the MCG.
Australia's most important player ran some sprints on the ground and then batted in the nets during an optional training session on Wednesday, a day out from the fourth Test against India.
The home side was sweating on Head's availability because of a quad strain, with the star left-hander hurt on the last day of the third Test at the Gabba.
That result left the series tied at one-all.
"Travis is good to go, he'll play. He ticked off some final things today and yesterday, but no stress, no worries about injury for Trav," Australia captain Pat Cummins said after training.
"He'll go into the game fully fit. I don't think you'll see too much management of him throughout the game ... maybe around fielding if he's a bit uncomfortable."
Had Head been sidelined, it would have been a gigantic blow to Australia's hopes of regaining the Border-Gavaskar trophy.
The 30-year-old has been in rare form, smashing centuries in Adelaide and Brisbane to certify himself as India's most in-demand wicket.
Head has made 409 runs at an average of 81.80 across the first three Tests of the series, dominating India even as the rest of Australia's batters have faced significant issues against Jasprit Bumrah.
It would be a massive risk to take a proppy player into a crucial Test, with the series squared at 1-1 with two matches to come.
The temperature is expected to soar to 40C on day one, possibly factoring into the team winning the toss batting first.
"Traditionally it's been bowl first (at the MCG) but with the heat around ... it looks similar but probably a little bit better than what it has in previous years so decisions for the captains to make at the toss," Australia coach Andrew McDonald said on Tuesday.
"I think this wicket might offer the batters a little bit more in terms of the surface as the game draws on."
Sam Konstas has been confirmed to debut, ensuring he will become the fourth-youngest Australian Test player.
Head's fitness means there will be two changes. Victoria seamer Scott Boland will also come in for the injured Josh Hazlewood.
Boland returns to his home ground and the venue of his famous Test debut when he tore through England with 6-7.
"If we didn't pick Scotty here -- and I know I'm not allowed to declare the team because that's Pat's job -- but I don't think I'm coming to the ground Boxing Day if Scotty's not in the 11," McDonald had joked.