Australian paceman Ryan Harris frankly admits he’s out of form, saying he felt like a bowling machine as century-maker Hashim Amla piled on the runs in the second Test.

But the 34-year-old with a creaking body is confident he can turn it around in the series decider against South Africa which starts on Saturday in Cape Town.

Harris has claimed just three wickets in the first two Tests against the Proteas at an average of 74.33, and rarely felt at ease about his lack of rhythm.

Cynics would point to his age or a litany of injuries, the latest of which is a worsening knee condition which will be operated on shortly after the third Test, and suggest his time is up.

But Harris feels ready to deliver if Darren Lehmann maintains his faith in Australia’s best bowler in the back-to-back Ashes series.

“When I was bowling to Amla he was just driving me for fun. I just felt like something wasn’t right,” Harris said.

“As good as their batters are, I felt like a bowling machine. I was just bowling in the wrong spot and they kept driving me.

“I’ve got a bit of work to do over the next few days … minor little technical things that I’ve had problems with before and managed to fix.

“I’ll do some stuff with (bowling coach) Craig McDermott, and we’ll go from there.

“But I know I’m not far away. My pace is still good. It’s just a matter of consistency at the moment.”

Harris admitted his knee condition was worsening.

“It’s getting to the stage where it’s catching a lot more and clicking a lot more, there’s all those fragments in there,” he said.

“But I’ll push through this game, hopefully bowl better and get it fixed it up in a week and a half or two weeks.”