Finger injuries to Cameron Green and Mitch Starc mean Australia will take a re-cast attack into the third Test against South Africa.
Green will not bowl in the second innings at the MCG after an Anrich Nortje thunderbolt on day two left him with a fractured finger.
He is also out of the Sydney Test and will not play for Australia again until the Indian tour.
Starc also hurt the middle finger on his bowling hand attempting a difficult diving catch in the deep on Boxing Day.
He has been cleared to bowl in South Africa's second dig, but the tall left-arm quick is in some doubt for Sydney.
Australia will also look at playing an extra spinner at the SCG, while former captain Ricky Ponting touted WA allrounder Aaron Hardie as a potential selection bolter.
Tearaway paceman Lance Morris was also brought into the squad for the Adelaide Test against West Indies as injury cover and he could make his debut at the SCG.
"If we bring a spinner into the squad for Sydney it will be based on the conditions for Sydney," coach Andrew McDonald told SEN on Wednesday.
"We've got a lot of work to do here, we've got a few in the casualty ward and that's going to limit our ability to press the whole time in the second innings.
"There's a bit of information to suggest it will be a drier surface in Sydney so you could see a spinner added."
Green, who took 5-27 in the first innings, resumed batting on Wednesday after retiring hurt the day before with his swollen and cut finger.
Unlike Green, Starc will be able to bowl in the second innings.
"He'll play a role with bat and ball," McDonald said of Starc.
"He'll be limited, his capabilities probably won't be as full as he would like but he'll do a role for us.
"There hasn't been any talk of an operation so I'd say that's more a splint to get that fully healed over time."
With Green sidelined from bowling and Starc also hurt, that will mean increased bowling workloads for captain Pat Cummins and Scott Boland.
That potentially also will influence selections for the Sydney Test, depending on how the rest of the Melbourne match pans out.
