Former England captains Kevin Pietersen and Michael Vaughan say Peter Handscomb has lost trust in his technique as doubts emerge over his position in the Australian team after another low score.
The Victorian was dismissed in worrying fashion for 12 by James Anderson, who worked the batsman over with a series of pitched-up deliveries.
There is now a strong suspicion England have figured out Handscomb, whose unorthodox technique is under the microscope.
Handscomb appeared to change his approach on Tuesday, keeping his head towards the leg side of the ball, which prevented him from hitting it under his eye line.
"It was very evident he had lost complete trust in the way he was playing," Vaughan said.
Handscomb was in the form of his life when he broke into the team last summer but the runs have dried up. The 26-year-old is averaging 24.33 from nine hits at first-class level this season with only one half-century.
While his Test average is still lofty at 47.35, the No.5 has passed 50 only once in nine innings since his game-saving 72 not out against India in Ranchi.
Handscomb is likely to keep his place in the XI for the third Test, particularly if Australia win in Adelaide, but he is no certainty to still be in the side by the end of the series.
Victoria's Glenn Maxwell, the leading run-scorer in the competition with 590 at 73.75, appears to be the next cab off the rank after being put on standby for the first Test.
Maxwell is presenting a strong case for a recall after backing up his epic double century with 96 this week in the Sheffield Shield.
Pietersen, who is fifth on England's all-time Test runs list, says England can see Handscomb has doubts in his game.
"In Test match cricket you have to fiercely compete against the bowler," Pietersen said on the Channel Nine telecast.
"You have to make the bowler think you have everything right, even if you don't. You have to get that personality across, to me Handscomb hasn't had that personality across.
"It'll emphasise with Broad and Anderson targeting him they knew he wasn't happy with that technique. You can't have that in Australia batting at No.5.
"You can see it from a mile off, the players can, you just cannot do it.
"[If] you're battling your technique as much as that the guys on the field pick it up so quick."
Pietersen said Handscomb, a teammate of his at the Melbourne Stars, needed to get back to basics.
"[But] what do you tell him to do?" Pietersen said.
"He's been scoring so many runs with that technique which has got him into the Australia side which we're questioning."
Handscomb said last week he was comfortable with his game.
"I have batted deep in my crease for three years, I am not really that concerned. I batted deep last year and managed to hit balls on the stumps and made lots of runs," he said.
"I am not concerned, obviously I have got my plans, I just need to hit the ball, it's as simple as that."