Shaun Marsh is in the box seat to replace Chris Rogers, whether it be for the third Ashes Test or after the series.

Marsh retired on 101 against Derbyshire on Thursday, his second century on Australia’s tour of England.

Rogers remains in doubt for the third Test, which starts on Wednesday at Edgbaston.

The veteran opener is undergoing more tests to assess his balance issues, with team doctor Peter Brukner expected to provide an update on Friday.

Marsh filled in for Rogers at the top of the order when the 37-year-old missed two Tests in the West Indies due to concussion.

If Rogers is sidelined again, Marsh has confidence and some serious form in local conditions.

“My mindset over the last couple of weeks is making sure I’m ready to go if there’s an opportunity,” Marsh said.

“With every opportunity I get to play for Australia, whether it’s a Test match or tour match … I’m just making sure I’m ready to go and doing everything I can to score runs.”

Even if Rogers is passed fit, he is set to retire at the end of the Ashes.

That will provide Marsh a perfect opportunity to nail down his spot in the Test XI.

“You don’t want to look too far ahead. You keep your mind in the present,” the Western Australian said.

Marsh admits he was chomping at the bit to get on the park again, having sat on the sidelines since making an impressive 114 against Kent a month ago in Canterbury.

“It was nice to get in a game situation,” he said.

“It was nice to get some runs …as my innings went on I got better.

“I feel really comfortable with my game at the moment.”

Fellow opener David Warner picked up where he left off at Lord’s, celebrating his first ton on the Ashes tour before retiring on 101 off 108 balls.

Marsh was more methodical in the town that helped launch the industrial revolution, taking over four hours and 177 deliveries to reach three figures and also retire on 101.

Skipper Michael Clarke, who has scored two centuries in his past 26 Test innings, struggled to get going in tour game.

Clarke was out for 16 off 37 balls during the second session, paceman Will Davis finding the edge and Tom Knight snaffling a catch at slips.

Peter Nevill batted at No.6, two spots above Brad Haddin, suggesting the 29-year-old is well placed to keep his spot in the Test XI.

Nevill impressed in Australia’s 405-run win at Lord’s, scoring a polished 45 and snaring seven catches to equal Brian Taber’s Australian record for most dismissals on Test debut.

Haddin, who withdrew from the second Test due to family reasons, is set to share wicketkeeping duties with Nevill in the clash with Derbyshire.

Haddin received treatment from physio Alex Kountouris for what looked to be cramp, but recovered to score 32 before his stumps were rattled by Tony Palladino.

Mitch Marsh and Shane Watson were both caught behind down the leg side, having scored 53 and 61 respectively.

Harry White, aged 20 and on first-class debut, dismissed both allrounders.

Watson, who was replaced by understudy Marsh for the second Test, teed off and needed only 39 balls to bring up his half-century off 39 balls.

Pacemen Mitchell Johnson, Mitchell Starc and Josh Hazlewood, offspinner Nathan Lyon and in-form batsman Steve Smith were rested from the fixture.

– AAP