He used to bowl to the left and bowl to the right, but now Mitchell Johnson is doing more than alright.

That's the opinion of Johnson's former Ashes strike partner Ryan Harris, who says the left-armer's ability to embrace the taunts of England's Barmy Army has been key to his strong performance in the first two Ashes Tests.

Harris, who is back in Australia having been forced into early retirement on the eve of the first Test, was full of praise for Johnson ahead of the third Test at Edgbaston, starting on Wednesday night.

Johnson has had a running battle with England's vocal supporters for most of his career and has admitted previously that their mocking cheers during the 2009 and 2010-11 Ashes series had a negative impact on his bowling.

But having silenced the Army with an historic performance in Australia 18 months ago, Johnson has decided to engage in some light-hearted banter with the home fans during the first two Tests of this series.

Quick Single: Johnson poised to join exclusive club

One of the more memorable moments came in Cardiff earlier this month, when Johnson repeatedly saluted the crowd as they sarcastically applauded him when he conceded his 100th run in England's first innings.

"He's dealing with it really good over there at the moment," Harris said.

"He copped a lot of it ... in Cardiff from the Barmy Army. They were everywhere, they were on the fence five metres away from him yelling out to him and trying to get to him and he was just playing with them.

"Going back there was a big Test for him but he's really enjoying the challenge. He's having a bit of fun.

"A lot of it was personal last time (in 2009) as it always is but he probably took it the wrong way. Now he's learnt to deal with it and have fun with it."

Having bowled without luck in Cardiff, Johnson showed signs of his fiery best in the second Test at Lord's, getting pace and bounce out of a lifeless surface to finish with 3-27 in the second innings.

Watch: Johnson back to his best at Lord's

The highlight was a brutal short delivery that accounted for Moeen Ali, with the left-armer getting significant lift out of a pitch that has been widely criticised for being too slow and batsman-friendly.

The state of the pitches used for the first two Tests has been a major talking point in the lead-up to the third Test, with the 22 yards of turf in the centre of Edgbaston the focus of much of the pre-match attention.

Harris says he was amused by the pitches used at SWALEC Stadium and at Lord's, adding that if England had indeed ordered the slow surfaces - despite their denials - the move had been counter-productive.

"They're going to deny it, but I find it really funny," Harris said.

"Obviously we didn't play well in Cardiff and it was very easy to sit there and say the wicket was rubbish. But the wicket wasn't very good at Lord's either and they got smacked so I'll be interested to see what they serve up tonight.

"They're costing themselves in a way with their bowlers. They've got (Jimmy) Anderson and (Stuart) Broad who are almost the two best bowlers in the history of English cricket. They're taking pace away from them and expecting them (to perform).

"They're not sure what to serve up because obviously they want to help their bowlers but they don't want their batters to face our bowlers on those wickets.

"Even that is confusing. So if they're thinking that, that's what we want."