Form not Fitness Behind Michael Clarke's Struggles, says Australian Batting Coach Michael di Venuto

Australia captain Michael Clarke's run of modest scores is not being exacerbated by his longstanding physical problems, according to team batting coach Michael di Venuto. (Full Ashes Coverage)

The 34-year-old Clarke is one of the outstanding batsmen of his generation, having scored over 8,500 Test runs, including 28 hundreds, at an average of more than 50.

But he has compiled just two centuries in his last 26 Test innings and hasn't made a fifty at that level since returning on Australia' recent tour of the West Indies. (Rogers Return to Australia Squad)

Clarke has had to cope with a chronic back complaint throughout his career but there are concerns that recent hamstring trouble has only made that condition worse.

He hasn't looked his typical elegant self at the crease so far on the Ashes tour and, with the five-match series level at 1-1 following his side's 405-run thrashing of England at Lord's, Australia would love to see Clarke back to his best come the third Test at Edgbaston, which starts on Wednesday. (Mitchell Marsh Warms Up for Ashes Test With Four-Wicket Haul)

Di Venuto said that was possible given Clarke was suffering from no more than the kind of lean spell which afflicts all batsmen at some stage of their careers.

"He seems unrestricted and he hasn't had a problem since, so I certainly don't think that's any reason why he hasn't been able to get a big score of late," di Venuto told Australian media during the drawn tour match with Derbyshire.

"I thought he looked pretty good in the World Cup final for his 70-odd. And he looked pretty good when he couldn't move when he scored a hundred when his back was no good against India.

"As batsmen, you go through little patches where things don't quite click," added di Venuto.

- 'Not too far away' -

Di Venuto, however, was confident a big score from Clarke was just around the corner.

"He's not too far away. He knows how to go about it and how to get himself back scoring runs.

"You can't do that in the nets. You've got to do that out in the middle," added 41-year-old di Venuto, who played nine one-day internationals for Australia but did not win a Test cap.

Clarke spent more than 90 minutes batting on Saturday, making 44 not out after promoting himself to open Australia's second innings at Derby.

Having fallen for 16 in the first innings, Clarke had made 19 on Saturday when Derbyshire wicket-keeper Harvey Hosein dropped a difficult diving chance.

That reprieve apart, Clarke was rarely troubled and, if not exactly fluent, a couple of drives hinted at better days ahead.

"I'm sure a big score is not too far away," said di Venuto.

"He's meticulous in his preparation. He's playing well in the nets, he's preparing well. He just needs a bit of luck."

Someone for whom luck is not an issue at the moment is Shaun Marsh.

His 101 against Derbyshire was the reserve opener's second hundred in three innings this tour.

Marsh is now waiting to see if the balance problems that forced opener Chris Rogers off the field at Lord's last Sunday also rule his fellow left-hander out of the third Test.

The older son of former Australia opener Geoff Marsh, Shaun's 14 Tests have yielded just two hundreds -- 141 against Sri Lanka at Pallekelle in 2011 and 148 against South Africa at Centurion in 2014.

Last year also saw him suffer the agony of being run out for 99 in the Boxing Day Test against India in Melbourne.

Di Venuto, though, has been heartened by Marsh's recent form.

"For someone who hasn't had a history of scoring a lot of hundreds, I think what we're seeing recently is fantastic," he said.

"It's brilliant we've got someone on the fringes ready to go."