As Pat Cash says, you've either got it or you haven't - and the former Wimbledon champion is convinced Australia's Alexei Popyrin has it.
One of only three teenagers in the world's top 100, Popyrin makes his much-anticipated Wimbledon debut on Monday after cutting a swathe through the qualifying draw.
The prodigy is among four Australians in action on day one the championships, up against Pablo Carreno Busta and upbeat about his chances of taking out the 2017 US Open semi-finalist.
But Cash says Popyrin has already exceeded all expectations since linking with the 19-year-old last month charged with honing his grasscourt skills.
"He's done a fantastic job, it's exciting. I haven't been working with him for a long time, but he's improved a lot. He's really got the grasp of it," Cash said.
"There's still plenty of work to do. There were things that needed to be fixed on the grass and he's gone a long way towards that.
"He's a very quick learner and I've been pretty impressed by that."
Not only impressed by Popyrin's work ethic and attitude, Cash loves Popyrin's temperament, which, at the highest level, is often what separates the best from the rest.
"This kid can play under pressure and he's a great athlete," the former Davis Cup hero said of the 2017 French Open.
"They are two things you can improve, but you kind of almost have it or you don't.
"He's got some technical things and bits and bobs to fix up and really it didn't matter if he didn't win a match on grass at all for the whole season.
"So this is a credit to him. I look through his results and when you're winning tiebreakers, that's a good sign even when you're losing matches.
"To me, that's a really good sign of being able to play under pressure."
Popyrin has designs on making a charge at the All England Club but Cash believes just being there is a bonus.
"He's here for experience. We want all the experience we can possibly get," he said.
"We wanted tough matches; we got that.
"He's had to play in the rain and wind at Queen's.
"We worked on his technique a bit, he's got great volleys ... it's all coming together."
Fellow Australians Ajla Tomljanovic, Daria Gavrilova and Astra Sharma also open their campaigns on Monday, all against women's seeds.
AUSSIES IN ACTION AT WIMBLEDON ON MONDAY (PREFIX DENOTES SEEDING):
Women's singles, first round
* Ajla Tomljanovic v 29-Daria Kasatkina (RUS)
* Daria Gavrilova v 8-Elina Svitolina (UKR)
* Astra Sharma v 27-Sofia Kenin (USA)
Men's singles, first round
* Alexei Popyrin v Pablo Carreno Busta (ESP)
