One of tennis's most respected strategists is imploring Alex de Minaur to tweak his flat forehand in order to take the next grand slam step.
Texas-based Australian coach and analyst Craig O'Shannessy, who helped Novak Djokovic emerge from his mid-career funk and capture four grand slam crowns, doubts de Minaur can win majors unless he turns his forehand vulnerability into a strength.
In becoming the first Australian since Lleyton Hewitt 20 years ago to reach three consecutive grand slam quarter-finals, all on different surfaces, de Minaur has proven he has the all-round game to go deep at the majors.
But O'Shannessy noted how the 25-year-old committed 35 forehand errors in his US Open quarter-final loss to Jack Draper, many of them dumped into the net, and says the world No.10 needs to improve his margin of error. "The two biggest weapons in today's game are the serve and the forehand," O'Shannessy told AAP.
"Alex doesn't have the speed on the serve to play through opponents like a Sasha Zverev does or even an (Carlos) Alcaraz, with a big serve that goes through the court.
"So then you've got to rely on other strengths of your game and Alex's forehand has always been an area that was open to attack."
O'Shannessy has also worked with several other players including emerging Australian star Alexei Popyrin and German Jan-Lennard Struff and said he always devised game plans for his charges to target de Minaur's forehand.
"Because Alex drops the left hand too early and hits it too flat," he said.
"So the net errors accumulate and it makes it difficult for him to hit it down the line.
"I know he was injured against Draper but too often I saw the exact same thing.
"So I do believe that towards the end of the year and in the off season Alex (should) improve his forehand technique, which would mean that he keeps his left hand on the throat of the racquet longer, which will naturally rotate his hips and shoulders better.
"That will automatically create a more rounded swing, help him get under the ball, help create more shape on the ball and take the net more out of play."
Asked if de Minaur could win a slam with his current technique, O'Shannessy said unequivocally: "Well, he hasn't yet".
"So it's not even an opinion. We just need to look at what the forehand's produced."
O'Shannessy is convinced that while de Minaur is a right-handed player, his left hand can bring him grand slam spoils.
"He's so good in other areas that it only needs a tweak - not an overhaul - because once you keep the left hand on longer and once the racquet stays up more, that will naturally create a more rounded swing and reduce the error count.
"His problem is getting the forehand errors out of the net."
De Minaur's run to the last eight in New York, in his first tournament back since suffering a hip injury at Wimbledon, has significantly improved his prospects of qualifying for the elite eight-man season-ending championship.
He currently sits eighth in the Race to Turin and will look to consolidate his position during the Asian swing.
De Minaur's more immediate concern will be recovering from the hip problem that flared again at Flushing Meadows.
The Australian No.1 said after his loss to Draper that he was unsure if he'd be fit for next week's Davis Cup qualifying stages in Spain.
