Australian skipper Pat Cummins and Nathan Lyon were Tuesday ruled out of the fourth Ashes Test against England with the veteran spinner facing surgery and an extended period on the sidelines.
Quick bowler Jhye Richardson and spinner Todd Murphy were named as cover in a 15-man squad for the clash starting on Friday at the Melbourne Cricket Ground.
Australia have already retained the Ashes with eight-wicket wins in Perth and Brisbane and an 82-run victory in Adelaide.
"Pat Cummins will miss the match as part of his ongoing management plan," Cricket Australia said, with Adelaide his first Test since July after lower back issues.
Steve Smith, who captained the team in Cummins' absence during the first two Tests, will lead the team again in Melbourne after missing Adelaide with vertigo symptoms.
"Nathan Lyon will have surgery on a torn right hamstring which will sideline him for an extended period," the governing body added.
Lyon, 38, damaged his right hamstring saving a boundary on day five in Adelaide fielding and hobbled off after.
In Adelaide, he claimed his 564th wicket to move clear of fellow Australian great Glenn McGrath and into sixth on the all-time Test bowling list.
Murphy is set to play his first home Test, with his seven previous Tests all overseas. He last played for Australia in Sri Lanka earlier this year.
Richardson was included after a four-year Test absence, during which he underwent three shoulder surgeries.
Scott Boland and Mitchell Starc are again set to lead the attack after pulling up well from Adelaide, with Michael Neser, Brendan Doggett and Richardson battling to join them.
Australia squad: Steve Smith (capt), Scott Boland, Alex Carey, Brendan Doggett, Cameron Green, Travis Head, Josh Inglis, Usman Khawaja, Marnus Labuschagne, Todd Murphy, Michael Neser, Jhye Richardson, Mitchell Starc, Jake Weatherald, Beau Webster