Australia have lost opener Rachael Haynes from their Test against India after the vice-captain was ruled out with a hamstring injury.
In a rough build-up to the Test for the hosts, Australia confirmed on Tuesday that Haynes would take no further part in the multi-format series.
Legspinner Georgia Wareham remains in doubt, racing the clock to beat a quad injury in time to play in pink-ball Test on Thursday.
But there is some good news, with Beth Mooney on track to beat her own hamstring woes and likely to replace Haynes at the top of the order.
Haynes met with team staff on Monday night after being told the news, and will now fly back to Sydney to be with her heavily pregnant partner.
"Unfortunately the hamstring's no good," Mott said.
"It's a pretty tough one, I had dinner with her last night. She's devastated obviously.
"Test matches don't come around too often. She's a key member of our squad so yeah thoughts with her at the moment.
"It's probably a little bit bittersweet I think. From a human point of view it will be good for her to get back but we're going to miss her a lot."
Haynes' injury will almost certainly see a reshuffle in Australia's order from their last Test in 2019.
Ash Gardner would be expected to move into the top six, while there is scope for George Redmayne to debut as a specialist batter.
Annabel Sutherland could also be an option to debut, with several new faces in the bowling attack including teenager Hannah Darlington.
The loss of Wareham would be a massive blow for Australia, given she is the only wrist-spinning option in the squad.
The Victorian was left out of Australia's team for their last Test just before the toss, denying her the chance to earn her baggy green.
"Georgia is ticking all the boxes for her return to play," Mott said.
"Once again was very sensible around that she felt something quite early and got treatment on it.
"She has been doing everything she can to be to be right.
"She's a key member no matter what the wicket serves up she's a wicket-taker. And she's an incredibly good thing for this team."
Australia lead the multi-format series 4-2, with four points up for grabs in the Test and two points for each of the three Twenty20s.
Australian Associated Press