Australia quick Peter Siddle ready to lead from the front on day five

Australia paceman Peter Siddle believes South Africa's ultra-defensive batting approach could play into Australia's hands as the hosts moved towards victory on day four of the second Test in Adelaide.

Disappointing

Australia will look to make further inroads early on, knowing they have just three specialist bowlers at their disposal with pace spearhead James Pattinson sidelined and out of the remaining four Tests of the summer with a rib injury. "It is disappointing," Siddle said of Pattinson's latest injury. "I think everyone knows he's going to be down and not going to be a happy chap at the moment. "He's still confident. He's just disappointed he can't get out there now and back us up and have a crack. "It's a disappointing time for him but he'll come back strong." In Pattinson's absence, the onus will be firmly placed on Siddle and Ben Hilfenhaus to bowl well, alongside off-spinner Nathan Lyon, who took two wickets for 15 runs today. "Tomorrow morning we've just got to be as fresh as we can be, especially Hilfy and myself," Siddle said. "Hopefully (we can) get a bit of reverse swing going. We know we've got the second new ball as well and an opportunity to have a crack at them with that. "We've still got a couple of options up our sleeve. "Nath is going to play a big role at that other end and hopefully get a few balls out of the rough and keep working them over. "He is going to have to hold up that end for the rest of this innings and the quicks from the other end. "If we can keep building the pressure and keep working away I think the six wickets will come around."