“He is a very shy boy, but I think now he has found his way and, importantly, developed that ego to take on the likes of Djokovic.”

Warwick was one of Australia’s top male players in the 1970s and 1980s, winning three singles titles and winning four major doubles titles with Mark Edmondson. He lost the 1980 Australian Open singles final to Brian Teacher, and reached a career high rank of No.15.

Warwick said the Montreal win last month was a catalyst for Popyrin’s career to take off. He beat Andrey Rublev (6), Hubert Hurkacz (8) and Grigor Dimitrov (9) – and two others in the top 20 – on the way to victory, meaning Djokovic was Popyrin’s fourth top 10 scalp inside a month.

“He has gone close with a bunch of top guys, but he really hasn’t been consistent, until the last 18 months. He has started to have a lot more wins and now he has broken through with the Montreal win. That was a game-changer for him, because it lets him know I can do it,” Warwick said. “He is a threat to anyone.”

For his part, Popyrin is sticking stubbornly to his “stay in the now” mantra.

“I’m not thinking that far. I’m going to give you the cliche answer I always give: It’s always the next match for me. I focus on the next match and that’s it,” he said in New York.

“My focus is on Frances. If I get past that, then we’ll focus on the next one. The biggest part about Montreal was I was able to back up big wins. For me, that’s something that I have really had to work on. I’ve had the capability of winning a big match but not being able to back it up. This week and Montreal I was able to do that.”

Tiafoe’s showdown with Popyrin has not surprisingly been afforded the prime-time slot on Sunday night in New York.

Loading

“He’s actually a really good friend of mine,” Popyrin said of his last-16 rival.

“We get along really well off the court. It will be interesting to play against him. We have practised a bunch of times. He’s a very tricky player. Probably has some of the best hands on tour, comes into the net a lot, likes to mix it up.”