Marsh blowtorch scorches Essex

Scorecard: Essex v Australians

Mitchell Marsh stole the headlines from David Warner and Ryan Harris on day one in Chelmsford, blasting five sixes in his second-consecutive hundred to lead Australia to a mammoth 6-440 at stumps against Essex.

Marsh rode his luck in again registering 136no from just 151 balls, surviving three dropped catches - including one on 98 - but nonetheless the 23-year-old has heaped pressure on incumbent allrounder Shane Watson, who himself made a rapid 52 (50), ahead of the first Test in Cardiff next Wednesday.

Wicketkeeper-batsman Peter Nevill also made the most of his opportunity, crafting a well-made 78 before edging down the leg-side from Jesse Ryder on what was the final ball of the day.

Earlier, Warner and Harris took centre stage in an eventful opening morning, the former for his blazing 94 and the latter for his late withdrawal from the clash.

Harris's news was the first - and biggest - story of the day, with Darren Lehmann saying the paceman would be sent for scans after he pulled up with knee soreness from last week's game against Kent and as such would not be risked ahead of the first Test in Cardiff on July 8.

Peter Siddle, who also played in Kent last week, was named as his replacement.

Lehmann on Harris: "We pulled him out because he's sore, he's going to get some scans done and we'll have a better idea in a day or two" — Andrew Ramsey (@ARamseyCricket) July 1, 2015

Quick Single: Knee soreness sidelines Harris in Essex

Michael Clarke lost the toss but Essex skipper Ravi Bopara kindly acquiesced and allowed the tourists to have a bat in very hot conditions, and Warner and Chris Rogers promptly shared another half-century stand.

Rogers (21) was the first to go, with the score on 60, the left-hander being ruled to have edged Tom Moore behind - a decision he seemed somewhat nonplussed about.

He was followed immediately by Clarke, who was well caught at square leg by Ryan ten Doeschate from the first ball he faced, leaving Moore on a hat-trick in the first over of his first first-class match this English summer.

Adam Voges negotiated the hat-trick ball and then played second fiddle to the increasingly aggressive Warner, who threatened a century in a session before his 86-ball stay finally came to an end when he picked out Bopara in the gully just before the interval.

Warner was in devastating touch for his 94 // Getty Images

Watson's blazing half-century came in a hurry after lunch but the allrounder would have been disappointed to give his wicket away, bowled by ten Doeschate just as a big score looked on the cards.

Voges (49) was the victim of an unfortunate run-out with Marsh that saw the West Australian pair end up at the same end of the pitch, the senior partner impressing with a mature innings at No.4 that saved his side from some bother.

Nevill, 30, showed his experience as he calmly accumulated runs in the evening session to reach a milestone of his own - his first 50 for Australia. The keeper-batsman also enjoyed a life as Essex were made to rue some missed chances in the field.

Yet it's the form of Marsh, who added 10 boundaries to his collection of sixes in an innings that again demonstrated both patience and power, that could have major ramifications in the make-up of Australia's first Test XI.

"It's going to be tight isn't it," Lehmann said when quizzed following the performance of Marsh in Canterbury where he scored a blazing second-innings hundred and took a wicket in each Kent innings, while Watson was rested from the bowling crease.

"I thought he (Marsh) was exceptional in the second innings as was Shane Watson (who made 81) to be perfectly honest.

"We need ‘Watto’ bowling and he'll definitely bowl (against Essex) so that's going to be a key for us as well.

"I thought he bowled really well in the West Indies for a short amount of time, so we know that's important for us especially in England.

"He shapes the ball nicely so he's going to have to bowl well.

"We know the rough (first Test) line-up we want to go with but how that shapes up will still depend a bit on performance."

Harris now appears almost no chance to play the first Test after this latest setback, particularly considering the quality performances Australia's pace trio of Starc, Hazlewood and Mitchell Johnson impressed in the recent Caribbean Tests in his absence.

Lehmann, who as coach of Queensland several years ago claimed Harris was the first player he would name if asked to pick an Australia Test team, echoed Harris's recent view that it's results not reputation that will decide the XI for Cardiff.

"(There are) no credits for players as far as we're concerned," Lehmann said after the Kent match. "The two Test matches in the West Indies the three quicks who played there (Johnson, Starc and Hazlewood) got (30) wickets for us so that's really pleasing.

"At the end of the day, Ryan Harris has got to be fully fit and if he's doing that then he's a big part of our side or squad going forward.

"He's got to prove to us he can bowl 20 overs in an innings or roughly about (he sent down 16 and 14 against Kent) and make sure he's ready to go.

"If he can do that, he certainly comes into consideration."

Australia: David Warner, Chris Rogers, Michael Clarke, Adam Voges, Shane Watson, Mitchell Marsh, Peter Nevill, Ryan Harris, Mitchell Starc, Josh Hazlewood, Nathan Lyon.

Essex: Jaik Mickleburgh, Nick Browne, Tom Westley, Ravi Bopara (c), Jesse Ryder, Ryan ten Doeschate, James Foster (wk), Matt Salisbury, Aron Nijjar, Jamie Porter, Tom Moore.