Aus paceman Siddle ruled out of second Test vs SA

Australia paceman Peter Siddle has been ruled out of the second test against South Africa in Hobart with a lower back injury, Cricket Australia said on Tuesday.

Siddle had scans after the 177-run loss in Perth on Monday and they showed "low grade bone oedema" around an old stress fracture, CA said in a media release.

"We are hopeful that this will resolve relatively quickly, but have withdrawn him from the squad for the second test match in Hobart," team physiotherapist David Beakley said.

"We will monitor his recovery and have a better idea of when he will return to play in the next week or so.”

Selectors had brought Tasmania fast bowler Jackson Bird into the squad as cover for the bowling attack, with uncapped Joe Mennie likely to debut in place of Siddle on Saturday.

Australia trail 1-0 in the three-match series, with the third test to be played in Adelaide from November 24.