Injury worries for David Warner and Mitch Marsh have clouded Australia's Boxing Day Test plans, but could prove beneficial for struggling No.3 Shane Watson.

Warner was struck a painful blow to the thumb by Indian fast bowler Umesh Yadav early in Australia's run chase at the Gabba on Saturday.

The in-form opening batsman was hit by a rising delivery in the second over of Australia's innings. He pulled off his glove, called for the physio and carried on batting, but was caught behind soon afterwards for six off the bowling of Ishant Sharma. Medical staff did not believe the thumb was broken but will monitor the injury in  coming days. With Marsh expected to be ruled out of the third Test with a hamstring injury and Ryan Harris confident he will be fit for a Boxing Day return, the selectors are pondering reinforcements for the third Test.

"I haven't spoken to Davey yet but he's a tough little character so I'm sure he will be eager to get stuck in on Boxing Day," said captain Steve Smith. "Mitch Marsh was struggling a bit with his running today so I think the physio will have a look at him over the next couple of days and make a decision."

Marsh was unable to bowl after the first morning in Brisbane. If, as expected, he is absent from the Boxing Day Test squad, to be named on Sunday, the selectors will have to decide whether to replace him with an all-rounder or a specialist batsman.

James Faulkner, called up in the United Arab Emirates as cover for Marsh, is an alternative all-rounder but it is unlikely he would bat as high as six. The form batsmen in the country are Ed Cowan and Adam Voges, with four and three centuries, respectively, in the first half of the Sheffield Shield season. Another option is South Australian batsman Callum Ferguson,  with a season average of 54 in the shield with two hundreds.

Watson's output at the top of the order is  in the spotlight after he added an eight-ball duck to his wasted start in the first innings.

He was stifled by Ishant Sharma before skying a hook shot that was caught comfortably by Dhoni, bringing his series tally to 72 runs at 18.

Watson has been restricted to four Tests this year because of injury but has a 2014 average of 23.

That's not enough to justify his place as a top-order batsman but the selectors might be reluctant to make radical changes to the top six. Watson's bowling was important at the Gabba with Marsh out of the equation. He sent down 27.4 overs for the match and bottled up an end while the likes of Mitchell Johnson attacked at the other.

"He built some outstanding pressure throughout the game," Smith said. "With a ball that's doing a little bit he hits outstanding areas."

Harris was missing from the attack that mauled India at the Gabba on Saturday because of a slight groin strain, but said he was on track for Boxing Day. "Going well, it was only a slight strain of the quad but I've done some good rehab over the last few days," the 35-year-old quick said. "I did a good run last night after play and there's no pain there so it's looking up. I'm pretty keen to play. I'm frustrated watching, Boxing Day is definitely on the cards."  He rated himself an "85-90 per cent [chance] if things stay as they are".

After Josh Hazlewood's match haul of 7-142 on debut at the Gabba, Mitchell Starc is the fast bowler likely to make way if the selectors are confident enough of the fitness of Harris to pick him. Starc's flagging body language and confidence was on show in the first innings, when he went wicketless and conceded 83 runs in 17 overs.

"It's about finding that happy medium where he gets his line and length right but still bowls at a good pace," said Smith. "Sometimes he might try a bit too hard."