Jackson Bird is on standby for the second Test against South Africa after veteran seamer Peter Siddle was ruled out with another back injury.

But ex-Test quick Ryan Harris said he would be surprised if South Australian speedster Joe Mennie did not run out in the baggy green in Hobart.

Scans on Tuesday revealed Siddle's old back complaint had flared up during the heavy first Test loss in Perth.

It ensures at least two changes to the Australian XI with opener Shaun Marsh (broken finger) also ruled out of the second Test.


It was another injury blow for 31-year-old Siddle who had just returned from back stress fractures that sidelined him for eight months.

"Peter Siddle had some lower back soreness at the conclusion of the first Test Match in Perth," Australia team physio David Beakley said.

"Whilst we expect bowlers to be sore after Test matches, this was slightly worse than we expected and given that he was returning from a significant back injury, we organised some scans today.

"The scans demonstrated some low grade bone oedema around his old stress fracture that is likely to be a flare up of his previous lower back injury.

"We are hopeful that this will resolve relatively quickly, but have withdrawn him from the squad for the second Test Match in Hobart."

Tasmanian seamer Bird has been placed on standby as cover but ex-Test quick Harris believed Mennie would step up against the Proteas.

Harris lamented Australia's lack of express strike bowlers but he agreed Mennie had done enough to earn a Test debut against South Africa after carrying the drinks in Perth.

"I would be surprised if Mennie isn't the next guy in," Harris said.

"I think we have got good bowling depth and had it for a while.

"What we do lack is that 145-150kph bowler, that big impact bowler.

"But there are not that many in the world to be honest."

Siddle suffered a back flare-up in the first Test - just his second first class match back from his long term injury.

But Harris dismissed the notion that Siddle and recovering Test spearhead Mitchell Starc were underdone in the first Test.

Starc is also on the injury comeback trail after suffering a nasty leg gash.

"They're probably better off being underdone than overdone, put it that way," Harris said.

"I used to always go into a game preferring to have not bowled as much because you want to be fresh.

"Should they have bowled a few more overs (before the first Test)? Maybe.

"But they wouldn't have played them if they didn't think they were ready."

Queensland's Joe Burns and South Australia's Callum Ferguson flew out for Hobart with Marsh out and a question mark over Adam Voges (hamstring).