Mitchell Johnson believes he may be a surprise weapon in Australia's armoury in the first Test against South Africa.

Speaking today, Johnson said touring bowlers like Dale Steyn could talk up their attack as much as they wanted, but he was still confident the Australians had a few surprises in store - particularly on their home turf.

"I trust our attack and I back us all the way," Johnson said.

"There's obviously going to be a little bit of niggle there with their pace, our pace, their top order, our top order... so they can talk as much as they want but we're just going to go out there and bowl like we've been bowling.

"I think we bowled quite well against New Zealand and these are our conditions, this is something that we're used to.

"Those guys (also) haven't seen me a lot in the longer form I guess so it's going to be pretty exciting for me to bowl at their top order.

"It's a bit of a look and see for them as well."

Fresh from a man-of-the-match performance in the second Test against New Zealand where he took nine for 69 across two innings, Johnson is looking forward to the expected pace and bounce of the WACA wicket when the two sides cross swords next Wednesday.

Despite the WACA's favourable conditions for pace, Johnson probably has better Test figures with the bat at this venue, having made a half-century in his one Test here against India last summer to go with a respectable five wickets at 28.8.

But the former Queenslander, who now lives in Perth and is expected to play for the Warriors later this season, says he has already talked to Australian pace legend Dennis Lillee about what is required to bowl more effectively at the ground.

"Bowling at the WACA, it's somewhere you've got to make the batsmen play," he said.

"If you're bowling outside off stump, it's pretty easy to leave here, so length's pretty important and your line. So we just spoke about little things like that."