Burns, Harris in for Marsh and Starc in Australian team

With a 2-0 lead, Australia go into the Boxing Day Test with a couple of changes - forced and by choice.

Ahead of the third Test at the Melbourne Cricket Ground (MCG), skipper Steven Smith confirmed that Mitchell Marsh has failed to recover from the injury he sustained during the second Test and Joe Burns will replace him at No. 6.

Another change Australia have made is bringing back Ryan Harris in for Mitchell Starc. Harris has recovered from his side strain that he sustained during the first Test.

"It is tough. Mitch Marsh has been playing some pretty good cricket. He played beautifully over in the UAE and was starting to find his feet. It's disappointing for him to be out through injury," Smith said.

"Joe Burns gets his opportunity on Boxing Day and it's going to be a very special week for him. But you've got to try to get that out of your mind. You've got to enjoy it. It's just another cricket game for him," the 25-year-old added.

"He's been hitting the ball really well. I'm looking forward to seeing him come out here and hopefully score a few runs in this Test match."

Burns, who opens the batting for Queensland in the Sheffield Shield, will bat at No. 6 for Australia. Smith was confident the massive change in role will not hamper Burns' chances.

"If you're batting in the top order in state cricket you can bat anywhere in the Australian line-up," the Australian skipper said.

"I just think that [starting at six] is the best way to go about it. Shane Watson is best suited in the top three and Joe Burns is going to slot in at six, and hopefully do a job for us there."

There was a scare about Watson as well, when he took a hit while batting in the nets. Smith, however, said his one-down batsman was fit and ready to play.

"I think he's OK," Smith said of Watson. He was a little bit shaken up with the hit the other day but he trained well yesterday and he's going well. I'm sure he'll be fine."