Australia captain Pat Cummins and spinner Nathan Lyon will miss the rest of the Ashes series, starting with the Boxing Day Test against England in Melbourne.

Cummins is being rested for the fourth and fifth Tests after rushing his return from a back injury to play in the decisive third Test in Adelaide. Spinner Lyon had surgery on the hamstring injury he suffered in Adelaide on Tuesday and there is no timeframe for his recovery.

Batter Steve Smith, who missed the third Test with illness, once again steps up to lead in Cummins' absence, while Todd Murphy comes in to replace Lyon. Pace bowler Jhye Richardson takes Cummins' place in the squad.

Australia have an unassailable 3-0 lead in the Ashes series and will look to move a step nearer to a 5-0 clean sweep when the fourth Test begins on Friday (23:30 GMT, Thursday).

Cummins suffered a back problem following the tour of West Indies in July. Before the Adelaide Test, he explained how he condensed a recovery period that should have taken three or four months down to six or seven weeks in order to take part in the Ashes. With the urn retained inside three Tests, the 32-year-old will not be risked and faces a wait to see if he will be fit for the T20 World Cup in India and Sri Lanka, beginning in February.

"We were taking on some risk," said head coach Andrew McDonald. "We've now won the series and that was the goal. To jeopardise him long-term is not something we want to do and Pat is really comfortable with that."

Australia squad for the fourth Ashes Test: Steve Smith (capt), Scott Boland, Alex Carey (wk), Brendan Doggett, Cameron Green, Travis Head, Josh Inglis, Usman Khawaja, Marnus Labuschagne, Todd Murphy, Michael Neser, Jhye Richardson, Mitchell Starc, Jake Weatherald, Beau Webster.

Lyon, 38, bowled only two overs in the first Test then was left out of the second. When he returned to the Australia team for the third Test, he took five wickets in the match before suffering the injury to his right hamstring making a diving stop on the boundary. It is the second time Lyon has been ruled out of an Ashes series - he suffered a calf problem in the second Test at Lord's in 2023.

"He's pretty shattered," said McDonald. "He'll be back around the team tomorrow and will be present at the Test match. He's facing a long recovery."

Smith's return will mean a further rejig in the Australia batting line-up after Usman Khawaja was left out for the third Test, then recalled on the morning of the game when Smith was ruled out. Left-hander Khawaja made scores of 82 and 40 in Adelaide and now seems likely to be retained, probably at the expense of Josh Inglis. Khawaja would bat at number five, wicketkeeper Alex Carey at six and all-rounder Cameron Green at number seven.

England trained at the Melbourne Cricket Ground on Tuesday and look set to make at least two changes for the Boxing Day Test. Jacob Bethell could come in for Ollie Pope at number three, while pace bowler Brydon Carse seems likely to be left out in favour of Gus Atkinson or Matthew Potts.