“He’s one of those kids that you have to hold back – don’t hurt yourself.
“When I sat down with him I said to him ‘If you don’t play, you will keep the 2cm tear. If you play, you’ll have a 4cm tear. You may end up scar tissue with that’s problematic for the rest of your career’.”
De Minaur eventually came to his senses.
At an emotional press conference in the main interview room at Melbourne Park, he pulled the pin on his 2020 Australian Open campaign.
The memory of sitting through that press conference has driven de Minaur to the third round of his home slam, where he will face fiery Italian Fabio Fognini.
“I understand youthful exuberance. I get it. It’s his home slam. And he was playing so well,” Masur said.
“But I think in his mind, he’s really set himself to do something here this year because he was so pissed off that he couldn’t make a mark last year. He really wants to make his mark.”
De Minaur has started the Australian summer in style.
After tight losses to Roberto Bautista Agut and Stefanos Tsitsipas in the ATP Cup, he breezed past Tennys Sandgren and Pablo Cuevas in the first and second rounds, respectively.
The Australian No. 1 has made a concerted effort to be more aggressive when break point opportunities arise. That approach has paid dividends.
“That has definitely been an overall theme in his thinking,” Masur said.
“We saw snippets of that last year. When you look at that ATP Cup match against Rafa, he literally came out of his shoes.
“He realises that yes, you can scramble and fight and run but you have to control a certain number of points.
“You can’t always be dictated to or use your speed to get out of trouble. That’s a theme he has really progressed in the last 12, 18 months.”
On Saturday night, Masur believes the 21-year-old has the game to absorb the powerful style of the Italian 16th seed.
Even if it’s without the support of a boisterous Australian crowd.
“Alex certainly responds to certain people in the crowd and he will get pumped and enjoy the atmosphere but he is more of a head down, introvert on the court. He will express himself but it won’t be a problem for him, playing with no crowd,” Masur said.
“He has always played a physical brand of tennis – a lot of scampering and defending. But he has always arrived at the Australian Open slightly busted.
“The fact that he had a lighter week – a couple of matches – and the draw was reasonable, that’s put him in a good position.
“I think Alex is really well placed to take care of this match and then he has to see who’s waiting for him and the kind of condition he’ll be in. It’s hard, because you can read too much into it when you are a match or two away from a potential match up.
“But I think he will beat Fognini.”
Sam is a sports reporter for The Sydney Morning Herald.