Todd Murphy has been picked ahead of Corey Rocchiccioli and Matt Kuhnemann in Australia's 15-man squad for the Boxing Day Test.
Australia revealed on Tuesday that Lyon required surgery to repair a torn right hamstring, an injury he suffered while diving to stop a boundary on day five of the third Ashes Test.
The 38-year-old will miss the fifth Ashes Test at the SCG, with Cricket Australia noting he will spend an "extended period" on the sidelines.
Lyon's future became a talking point when he was dropped for the second Ashes Test at the Gabba.
But the tweaker has previously made it clear he is far from ready to retire, having noted he wants to play into 2027.
"It's really unfortunate for him," Mitchell Starc said in Adelaide, speaking prior to Lyon learning he needed surgery.
"I'm sure it's a tough one to take. He contributed a lot in this Test match. He's helped us get to this victory.
"He's obviously had a layoff with his calf through England, so he's sort of more on board with the fast bowlers in terms of what rehab takes.
"I think he's still got that hunger to give more to Australia.
"That's all for him to think through. Hopefully it's not a huge layoff."
Beyond this Ashes series, Australia's next red-ball commitment is not until August with two Tests against Bangladesh in Mackay and Darwin.
That will kickstart the busiest 12 months of Test cricket in Australia's history, with up to 21 matches to be played in that period.
