MELBOURNE - Australia skipper Pat Cummins and Nathan Lyon were on Tuesday ruled out of the final two Ashes Tests 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 fourth Test starting on Friday at the Melbourne Cricket Ground.
Australia have already retained the famous urn with eight-wicket wins in Perth and Brisbane and an 82-run victory in Adelaide.
Cummins "won't play any part in the rest of the series", coach Andrew McDonald told cricket.com.au.
He returned from a lower back injury to lead Australia to victory in Adelaide in his first Test since July, taking six wickets in the match.
"That was a discussion that we had a long time out around his return. Yeah, we were taking on some risk. We've now won the series, and that was the goal," said McDonald.
Cummins will now target full fitness for the month-long Twenty20 World Cup in India and Sri Lanka, starting in early February.
"To position him for further risk and jeopardise him long term is not something that we want to do," said McDonald.
"Pat's really comfortable with that. If he had any setback in the build-in as well, we would have shut him down straight away."
Steve Smith, who captained the team in Cummins' absence during the first two Tests, will lead the side again in Melbourne after missing Adelaide with vertigo symptoms.