Batsman Travis Head was declared fit for the Boxing Day Test against India on Wednesday in a big boost for Australia while Scott Boland was confirmed as the injured Josh Hazlewood's replacement.

Aggressive number five Head is the highest run scorer in the five-match series, plundering centuries at both Adelaide and Brisbane.

He picked up a minor thigh strain at the Gabba and there were lingering concerns about his fitness, but skipper Pat Cummins said the left-hander was fine.

"Trav is good to go, so he will play. He just ticked off some final things today and yesterday," said Cummins. "No stress, no worries about injury for Trav, so he will go into the game fully fit.

"I don't think you'll see too much management of him through the game. Maybe around fielding if he's a bit uncomfortable, but he's fully fit," he added.

Head has slammed 409 runs at an average of 81.80 across the first three Tests, dominating India as other Australian batters have struggled from the threat posed by pace spearhead Jasprit Bumrah.

"It feels like the last 12 months he's been in this unbelievable vein of form and he just keeps going," Cummins said of Head.

"He's hitting the ball really cleanly and you can see the pressure he shifts back onto the opposition, literally from the first ball he walks out there.

"I'm loving that he is in our team. Long may it continue."

The five-match series is tied at 1-1 after India won by 295 runs in Perth before being crushed by 10 wickets at Adelaide. The rain-affected third Test in Brisbane was drawn.

Cummins confirmed two changes to the team with seamer Boland, as expected, in for the injured Hazlewood.

Teenage opener Sam Konstas had already been locked in to make his debut, replacing Nathan McSweeney.

The 19-year-old Konstas will become Australia's youngest Test debutant since Cummins took the field against South Africa at Johannesburg in 2011.

"I just remember being really excited and it's similar for Sammy this week," said Cummins, looking back to his debut.

"There's a level of naivety that you just want to go out and play, like you do when you were a kid in the back yard, you just want to take the game on and have fun and not overthink it.

"That's the message to Sam."

Australia: Usman Khawaja, Sam Konstas, Marnus Labuschagne, Steve Smith, Travis Head, Mitch Marsh, Alex Carey, Pat Cummins (capt), Mitchell Starc, Nathan Lyon, Scott Boland