Australia captain Pat Cummins will miss the first Ashes Test against England.
Cricket Australia has confirmed the 32-year-old fast bowler has not recovered from a back injury in time.
Former skipper Steve Smith will lead Australia in Cummins' absence.
Cricket Australia said that Cummins is back running and "expects to return to bowling shortly".
However, he will not be up to speed in time for the opening Test, which begins in Perth on November 21.
Cummins had indicated earlier this month that he would like to have been back bowling at least four weeks before the series begins.
His aim will now be to make the second Test in Brisbane, which begins on December 4.
Scott Boland, 36, is the likely replacement for Cummins in Australia's bowling attack, alongside Mitchell Starc and Josh Hazlewood.
Vice-captain Smith has stood in for Cummins six times previously, having captained Australia for three years until he was banned after a ball-tampering scandal.
Cummins has not played since Australia's Test series against the West Indies in July.
He was the leading wicket-taker with 21 scalps when England last travelled down under four years ago, a series which Australia won 4-0.
