Aussies' task is to keep Mitchell Johnson on fire: Darren Lehmann

Australia coach Darren Lehmann says his challenge is to keep man of the moment Mitchell Johnson on the boil with the team on the brink of wresting the Ashes from England's grasp.

The fearsome left-arm paceman grabbed his second consecutive man-of-the-match award after a thumping win in Adelaide on Monday as the home side took a 2-0 lead in the five-Test series. (Johnson enjoys terrifying England batsmen)

If Australia win the third Test starting in Perth on Friday, they will reclaim the Ashes they lost in 2009 and Johnson will be raring to go at a ground where he has claimed 36 wickets at an average of under 20.

Johnson already has 17 wickets in this series at 12.70 and is on top of his game as he bids to bowl Australia to a series-clinching victory at a ground where they have won their past six Tests against England. (Related: Clarke wants top Test ranking)

Lehmann, who has helped mastermind Australia's turnaround after their 3-0 series loss in England earlier this year, said the task was to keep the 32-year-old firing on all cylinders.

"He's been impressive. He's confident. Our challenge is to keep him going and bowling that way. It's exciting for Test match cricket," Lehmann said.

"It's exciting to see bowlers bowl fast, or spinners turn it square. You've got to adapt and improve your technique. It's always exciting to see guys bowl at those speeds.

"When a bowler is bowling at 150 kph (93 miles per hour) it's not easy. When I was playing, 150 kph would get me out every time. Simple fact of life, it's tough work."

With momentum on their side, Lehmann wants his team to keep on doing what they've been doing in Perth. (Aussie media write off visitors)

"They're pretty driven this lot. I'm really pleased with what they're bringing to the table and how they've gone about it in the last few Test matches," he said.

"Obviously changed a few things in England and they've been really good. They're trying to get the right goal for Australian cricket. That's not just the short-term, that's long-term."

Lehmann said he expected allrounder Shane Watson to bowl more in Perth after being used sparingly in Brisbane and Adelaide, where his focus was on his batting.

"He's been under-bowled. He could have bowled more in the first Test and in Adelaide," he said.

"From our point of view that's handy. But he's an allrounder, so we expect him to bowl more. And he'll certainly have to in Perth if the weather is hot."

The Australians have been dominant at the WACA, where England's only win came in 1978, but the tourists' captain Alastair Cook insisted the past was irrelevant.

"You can say that we haven't won there for however many years, it's of total irrelevance to this team," he said.

"We have to go there as this side in 2013 and deliver something very special or we're not going to do what we've come to do."