Watson missed the 2006-7 Ashes series with one of string of hamstring injuries that have afflicted him over his career and sustained another in the series-deciding one-day loss to India in Bangalore on Saturday.
"It's not too bad," Watson told reporters on his arrival at Sydney, where he will have a scan later on Monday.
"I've had a few niggles like this even over the last eight or nine months, so hopefully it won't be too bad at all or put me out for too long.
"My body's really adjusting to bowling, it's just an unfortunate little hiccup in the last game. It would've been nice to get home without any niggles.
"Being here it'll give me a week or two to be able to hopefully freshen up and ready to go for the first test."
The loss of Watson would be a major blow for Australia's preparations for the opening test, which starts in Brisbane on Nov. 21.
The hosts have already lost two frontline seamers Mitchell Starc and James Pattinson to back injuries for all or part of the series, while a third, Jackson Bird, is also battling to overcome a lower back stress fracture in time for Brisbane.
Watson, who has been plagued with soft tissue injuries throughout his 46-test career, batted against India after receiving treatment from medical staff.
"The situation of the game meant I needed to come out and try and give us a chance to win," the 32-year-old said. "Unfortunately it didn't work out.
"But in the end, I don't think I injured myself too much more."
Watson scored 176 in the drawn fifth and final test in the away series against England at the Oval and, if fit, would bat at number three in the return series.
His economical medium pace and value as a timely wicket-taker would also be sorely missed as Australia look to stop the tourists winning a fourth successive Ashes series.
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