Australia captain Meg Lanning will miss the entire Women's Ashes following shoulder surgery that is set to rule her out for six to eight months.
The injury to her right shoulder hampered the world number one batter during the recent World Cup.
The Ashes start in Brisbane on 22 October with the first of three one-day internationals, followed by one Test and three Twenty20 internationals.
"It's very disappointing to be unavailable," said Lanning, 25.
"It's an incredibly special occasion for any cricketer to be a part of and I wish the team all the best as they set out to retain the Ashes.
"I'm looking forward to getting stuck into my rehabilitation and returning to cricket as soon as possible."
Lanning's return date will "become clearer once she has commenced rehabilitation", said team physiotherapist Kate Mahony.
Cricket Australia have not yet announced who will replace Lanning as captain.