Pat Cummins and Josh Hazlewood are setting their sights on returning to action in November when Australia's ODI series against South Africa starts.
Cummins has played the last 13 Tests in a row but hasn't been able to recover from a back problem in time to be considered for the series against Pakistan in Asia.
Hazlewood has a similar issue and the absence of the fast bowlers leaves the new-look team - already without superstar duo Steve Smith and David Warner - with big holes to fill.
For the series against Pakistan, Tim Paine's side will be reliant on Mitchell Starc to spearhead an inexperienced bowling attack.
Selectors are set to monitor the two four-day games of the A series in India, where Chris Tremain, Brendan Doggett, Joel Paris and Michael Neser have opportunities to earn senior selection.
Jackson Bird will also be in the frame for a Test recall along with Jhye Richardson.
The absence of Cummins and Hazelwood makes it more likely that Australia will play two spinners against Pakistan. Nathan Lyon will be one, while Ashton Agar, Jon Holland and the uncapped Queensland leggie Mitchell Swepson are the other contenders.
Australia team physio David Beakley said: "Pat and Josh are progressing well from their lumbar bone stress injuries but are not bowling so unfortunately they will not be at the level required for Test match intensity come October.
"Barring any setbacks, we are hopeful that Pat and Josh will return via the back-end of the JLT One-Day Cup, with the aim of them being available for the ODI series against South Africa in November as they build towards the Indian Test series."
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