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.
In-form Australia batter Travis Head following a net session on Christmas Day in Melbourne. (James Ross/AAP PHOTOS)
"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.
"You can see the pressure that he shifts back onto the opposition, literally from the first ball that he walks out there," Cummins said.
It would be a massive risk to take a proppy player into a crucial Test, with the series squared at one-all 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.
On Tuesday, Australia coach Andrew McDonald said the heatwave might make Cummins and rival captain Rohit Sharma reconsider bowling first, which has been the usual MCG option.
Cummins said he would reserve judgement on his toss call until Thursday morning.
"It (the heat) is another layer - you get to the ground tomorrow, you look at the pitch," he said.
"You get a bit of a sense of what (sort of) day it's going to feel like and make a decision from there. It is a factor ... I don't think it scares us too much."
Sam Konstas has been confirmed to debut, ensuring he will become the fourth-youngest Australian Test player.
Cummins, who was a year younger than the 19-year-old when he debuted, is urging Konstas to play with freedom.
"I was saying this to Sammy the other day, I remember as an 18-year-old thinking 'I got a lot more leeway, because I was young' - almost publicly," Cummins said.
"I almost felt like if I didn't have a great game, it wasn't my fault, it was the selectors' fault for picking me ... they're the idiots who picked an 18-year-old.
"It's Boxing Day, it doesn't get any better than this, just enjoy the moment."
Scott Boland and Usman Khawaja during a Christmas Eve net session at the MCG. (Joel Carrett/AAP PHOTOS)
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.
37°C