Sydney - Injured skipper Michael Clarke faces a fitness deadline this week to have any chance of playing for Australia in next month's first Test against India, chief selector Rod Marsh said on Monday.
Clarke was named in a 12-man squad subject to a fitness test on the left hamstring he injured in the recent one-day series against South Africa in Perth. He also continues to undergo daily treatment for an ongoing back condition.
The captain needs to prove by Wednesday that he is ready to play in a two-day match against the tourists in Adelaide, starting on Friday.
Should he pad-up and recover well, he will take his place in the Brisbane Test side, said Marsh, adding that no risk would be taken with Clarke's long-standing troublesome hamstring.
"With his recent history, we can't have him breaking down in the first innings of a Test match," Marsh told reporters.
"We would never ever rest the Australian captain in the first Test of a series. But if he's not fit, obviously he can't play."
Marsh added that "we can safely assume he won't be playing the Test" if he is not ready by Wednesday, with the subsequent two-day game essential for him to prove his fitness.
No possible Test replacement has been named.
While the focus was on Clarke, uncapped New South Wales paceman Josh Hazlewood was rewarded with a call-up to the squad for his strong recent performances against South Africa in the one-day series.
It is his first inclusion in a Test squad since 2012-13.
Hazlewood, 23, captured nine wickets in the series against South Africa, which Australia won 4-1 on Sunday to return to the top of the International Cricket Council one-day rankings.
"Josh is a young player of great talent and he thoroughly deserves this opportunity," Marsh said.
"He has impressed in the recent one-day series and we are excited to see what he can produce if given the opportunity in Brisbane."Veteran paceman Ryan Harris returns to the national squad following knee surgery and will play in this week's round of Sheffield Shield matches as part of his build up to the opening Test from December 4.
"If my knee doesn't feel right at all I will tell them (selectors), but I will do anything to play that first Test," Harris told reporters.
"I am not trying to unselect myself. But I am not going into it underdone. You can't afford to drag one bloke into a Test match."
Harris has told the selectors he needed one more shield match this week to be ready.
"I made it clear I wasn't happy with where I was at. It's perfect that I get another game," Harris said.
If Harris is fit, Hazlewood and Peter Siddle will battle for the final berth in the Test side, with offspinner Nathan Lyon expected to be retained.
Senior batsman Shane Watson returns to replace Glenn Maxwell at No 3, while left-armer Mitchell Starc has been squeezed out of Australia's pace attack.
Australia - Michael Clarke (captain), Brad Haddin, Ryan Harris, Josh Hazlewood, Mitchell Johnson, Nathan Lyon, Mitchell Marsh, Chris Rogers, Peter Siddle, Steve Smith, David Warner, Shane Watson.