Derby: Shaun Marsh scored his second hundred in as many tour matches as Australia made 413 for nine on the first day of three against Derbyshire at Derby on Thursday.
But skipper Michael Clarke`s quest for lengthy time in the middle was cut short when he fell for 16 to 19-year-old paceman Will Davis.
Clarke has scored just two hundreds in his past 26 Test innings but Marsh said: "He`ll be fine. He`s been a world-class player for a number of years now.
"A big one is just around the corner, there`s no worries there."
Marsh, who is in line to replace Chris Rogers should the veteran opener be ruled out of next week`s third Test at Edgbaston, made 101 before retiring out as did fellow opener David Warner.
Davis and fellow Derbyshire debutant Harry White shared five wickets in their maiden first-class innings.
The 19-year-old Davis led the attack with three for 63, dismissing both Adam Voges and Peter Nevill for one.
Meanwhile 20-year-old Derby-born left-arm paceman White had two for 85 from 19 overs.
Rogers`s place at Edgbaston has been called into question after he suffered a dizzy spell on the final day of Australia`s 405-run win over England at Lord`s on Sunday that levelled the five-match Ashes series at 1-1.
Cricket Australia said Wednesday that, following examination by a London-based specialist, Rogers was suffering a balance problem in the inner ear.
The first innings at Lord`s saw Rogers score a Test-best 173.
Rogers, who is to have further tests in London, was not scheduled to play against Derbyshire in any event.
Warner, who made 83 in the second innings at Lord`s, was rarely troubled after Clarke won the toss.
His one awkward moment came shortly after he had completed his fifty when Davis struck him in the groin.
But, after receiving some on-field attention, Warner batted on and shortly before lunch lofted off-spinner Scott Elstone for six.
Warner went to his hundred with a cover-driven boundary off Jonathan Clare and then walked off, having faced 108 balls including 13 fours and a six.Clarke, whose best score of the tour thus far was 56 in the opening match against Kent, did not look at ease on Thursday before he edged the lively Davis to Tom Knight at second slip.
Two balls later, Davis had a second first-class wicket when Voges was lbw.
Australia, 93 not out at tea, saw Shaun Marsh, the son of former Ashes-winning opener Geoff Marsh, follow Warner`s lead when he too walked off after reaching three figures, having faced 177 balls including 14 fours and a six.
It was his second hundred in as many matches following his 114 against Kent.
"If an opportunity does come, I`m just making sure that I`m ready to go" said Marsh.
Australia included both Brad Haddin and fellow wicket-keeper Nevill in the XI to play Derbyshire.
First-choice gloveman Haddin didn`t play at Lord`s after withdrawing because of "family reasons", with Nevill impressing on his Test debut.
Both players are set to share wicket-keeping duties in this match ahead of the third Test, which starts on July 29.
Nevill gave Davis his third wicket when a square cut was caught at cover-point.
Mitchell Marsh, Shaun`s younger brother, made a fifty as did fellow all-rounder Shane Watson (61).
Haddin made 32 before he was clean bowled on the walk by Tony Palladino.