Matthew Hayden has urged Marcus Harris to put the cut shot away until after he reaches three figures in his innings and to playstraighter for longer.
Harris has been one of Australia's best finds of the summer, making starts in all but one of his eight innings, but he is yet to turn any of those scores into a century.
The left-hander was caught at point on 44 in Australia's series-opening Test win over Sri Lanka in Brisbane, and has also been out trying to hit balls square from well outside off stump on three other occasions this summer.
Australia's most prolific Test opener Hayden, a fellow lefthander who amassed 8,625 runs at the top of the order with 30 centuries, said Harris had to restrain himself for longer in order to thrive at Test level.
"I've been really impressed with Harris but I think he plays too square of the wicket for an opening batsman," Hayden told AAP.
"He needs to straighten his game up and play straight and bat for long periods of time. And be disciplined to the point of 'I'm not going to play a cut shot until I'm on 120 or 130'."
Hayden watched on in Brisbane while helping raise over $50,000 for rural drought relief, but was again frustrated by Australia's century drought this summer.
It's a problem he believes that goes back to Sheffield Shield cricket, where less big scores are being made than in his era.
Every Australian batsman averaged between 20 and 40 in the series against India, while Australians have eight times been dismissed between 60 and 85 this summer - including Harris and Travis Head twice.
"It's a mindset thing," Hayden said.
"I used to find that in the 30s or 60s I was always vulnerable because at 30 you're just starting to break through as an opening batsman, you've done all the hard work and you're starting to feel the ball.
"And then at 60 you're starting to get touch, so you start to explore what that looks like.
"But to get big runs you have to go 'okay well I know I'm vulnerable here now, I'm going to work my way be it a time goal or partnership goal, I'm going to work my way through a stage of the game'."
