The selectors have added Tasmanian top-order batsman Alex Doolan to the squad as cover for Watson, who aggravated his groin while bowling in the first innings of Australia's eight-wicket trouncing of England in the Boxing Day Test.

All-rounder James Faulkner and fast bowler Nathan Coulter-Nile are also on standby for Watson and Ryan Harris, but Watson is believed to have recovered well from his innings of 83 not out to help Australia to victory at the MCG and is confident he will be fit for the all-rounder's role in Sydney.

''It [the groin] has been niggly at certain times over the past year [but] it recovers very well. We know how to treat it. It shouldn't put me out,'' said Watson, who bowled four laborious overs in the second innings in Melbourne.

Harris remains bullish about finishing off the series, but he is in doubt because of cartilage problems in his knee and blistered feet.

The selectors have the option of making up to three changes for the final Test - Doolan for Watson, Faulkner for George Bailey and Coulter-Nile for Harris - but bowling coach Craig McDermott is confident they won't be required.

Bailey will be hoping Watson is fit to bowl, having so far been unable to put his own position beyond doubt. The preference for an all-rounder could see Faulkner replace him in the middle order.

''There is potential for that, the options are there. Hopefully all 11 guys who have been playing the series will be fit and get back on the park again,'' batting coach Michael Di Venuto said.

Di Venuto admitted the team needed more from the Tasmanian captain, especially in the first innings of matches, in which Bailey averages 15.75.

''Probably like the rest of the top order in the first innings, he [Bailey] has really battled. He hasn't quite done the job yet, he has had a couple of innings - a good 50 in Adelaide, a little cameo in Perth, with the situation he has come out and played nicely. He is playing well, hitting the ball well, but it is first-innings runs that are the key to making life a lot easier to win Test matches.

''Alex Doolan is providing cover for Shane if Shane doesn't come up. He moved pretty well out in the middle during his 80-odd, so we are all hopeful he will be up and about for Sydney in a batting and bowling capacity.''

Harris is desperate to play, but he showed signs of weariness in Melbourne, bowling just 10 overs in the second innings.

With an important Test series against South Africa on the horizon, he won't be risked if there are concerns about him getting through the Test after a five-day break. He is likely to need an operation on his knee at some stage next year, but medical staff are hoping to get him through the South Africa series first.

''Rhino is a bit sore, but I don't think anybody played too many Test matches as a fast bowler without pulling up sore at some stages,'' McDermott said.

''So he has got some niggles. And so has Watto, but Watto ran well between wickets yesterday, he is pretty mobile. So, I am pretty confident they will all be involved in the next Test match.''

Harris battled through the Melbourne Test with sore feet from a new pair of boots. ''Most play with new boots all the times. He cuts out a certain part of the boot and I don't think it was done quite correctly by whoever cut it for him,'' McDermott said.

Doug Bollinger has been omitted from the Test squad and released to play in the Big Bash League.