Shane Watson may yet play in the opening Ashes Test after scans showed his hamstring injury was only a low-grade strain, but his chances depend on how he responds to "intense treatment and rehabilitation" over the coming days. Watson suffered the injury while bowling during Australia's final ODI in India on Saturday, less than three weeks before the Gabba Test.

His availability in Brisbane will have ramifications for the balance of Australia's side, for if he is ruled out or unable to bowl, the selectors would need to consider another allrounder to provide an extra bowling option. Watson remains confident he will be fit to bowl during the Test, but Australia's physio Alex Kountouris said much would depend on the next few days.

"Since returning home from India, Shane has been assessed and had scans on his injured left hamstring, which confirm a low-grade muscle strain," Kountouris said. "He will have intense treatment and rehabilitation in Sydney over the coming days and just how well he responds to this will determine how quickly he can resume full training and match preparation.

"It goes without saying that Shane and the medical team will be doing everything possible to get him fit and available for selection ahead of the first Test. We'll be assessing him on a daily basis and expect to have a clearer picture of his progress later in the week."

Whatever the case, Watson is unlikely to have any first-class cricket before the Ashes opener, given that New South Wales have only one more Sheffield Shield match - against Queensland in Brisbane starting next Wednesday - before the Test. Watson ended the Ashes tour of England with 176 at The Oval, which effectively locked him in as the incumbent No.3 for the start of the home series.

If Watson is fit to bat and bowl, he would be expected to remain at first drop with another batsman, perhaps the Tasmania captain George Bailey, to slot in down the order. However, should Watson be ruled out it might affect Bailey's chances of a Test debut, for he is considered a middle-order player rather than a batsman who could fit in the top three.

In that case, Bailey's Tasmania team-mate Alex Doolan might be considered for his first Test as the No.3, while James Faulkner may take the allrounder's role and Brad Haddin could move up to No.6. However, as well as Watson's recovery over the next few days, the coming week will also provide clarity on the form of several batting contenders, with three Shield matches and an Australia A v England tour game all starting on Wednesday.