England seamer Kate Cross will not feature in the first Women's Ashes one-day international due to a back injury.
Cross, 33, missed the one-off Test match against South Africa in December after suffering a back spasm during the third ODI of that tour.
Lauren Filer and Lauren Bell are the front-line seamers selected alongside all-rounder Nat Shaver-Brent.
Cross was unable to run in the tour's only warm-up match on Thursday, with only 28.2 completed due to rain in Sydney.
She revealed on the No Balls with Alex Hartley podcast that she had an epidural to try and regain fitness for the first match but was unable to prove her fitness in time.
It is a big blow for England, as Cross is the most experienced and reliable seamer with 72 caps since her debut in 2013, while Weiler and Bale have played 12 and 16 matches respectively.
The multi-format Ashes began on Saturday (23:30 GMT) with the first three ODIs, followed by three T20 matches and one Test match.
It has not been confirmed whether Kroos will be available for the remaining ODIs, which will be played on January 13 in Melbourne and January 15 in Hobart.
She is not in England's T20 squad but is likely to play in the Test if possible.
Australia retain the Ashes, so England will need to win the series outright in order to reclaim the trophy.
