A steely look appears in Patrick Mouratoglou's eyes on a glorious afternoon in Paris as he declares "I don't see any limit on what they can achieve" when quizzed about two teen proteges who enabled him to celebrate a French Open double.
The charismatic Frenchman is best known for coaching Serena Williams over the last six years, playing a key role in the legendary American taking her tally of grand slam singles titles to an Open-Era record 23.
Mouratoglou exudes huge confidence when talking up Williams' ability to put an injury setback on her grand-slam comeback at Roland Garros behind her and mount a strong challenge at Wimbledon.
It is not only the prospect of short-term success that fuels the meticulous mentor, though, far from it.
Just a few days after Williams pulled out of the second major of the year, Mouratoglou was celebrating two triumphs at the clay-court major in his homeland a day after his 48th birthday.
American Cori Gauff was crowned girl's singles champion just a few months after turning 14 and 16-year-old Chun Hsin Tseng took the boy's title in the French capital.
The promising duo's natural talents been nurtured at the Mouratoglou Tennis Academy, a state-of-the art of the resort on the French Riviera where hundreds of players of various ages, abilities and nationalities are given the best possible opportunity to fulfil their potential.
In an exclusive interview with Omnisport, the astute Mouratoglou enthused over what the future may hold for the newly-crowned French Open champions.
"Both of them are fantastic. Cori is only 14 years old, she reached the final of the US Open juniors last year at the age of 13 - the youngest ever in the history to do that." he said.
"She is fantastic, she can become a top, top player. I believe in her a lot.
"Chun Hsin Tseng won Les Petits [a prestigious tournament in France] as an Under-14, he also reached the final of Australian Open this year. They are both super-promising and I think they can go really, really high."
Mouratoglou breaks off from the interview briefly to shake hands with Gauff's father before going on to talk up another trio of young players who have could reap the rewards of his expertise.
"I set up a group called Mouratoglou Team with three players: Alex Popyrin, Stefanos Tsitsipas and Thanasi Kokkinakis - three young players that I think potentially have a good future." he added.
"We set up the best possible team for them to achieve their goals. I am happy with their progress and I am happy with those just under them. At every age group we have some of the best players in the world at the Academy.
"I don't see any limit on what they can achieve. They are young, they are hungry, they are talented, they are working hard and I think they have a very good environment around them. Let's start the journey and go as far as they can and not put any limits on what they can achieve."
Those who voice concerns over the lack of up-and-coming talent with the likes of Williams, Roger Federer and Rafael Nadal in the twilight of their careers should take heart from Mouratoglou's words.
There is no doubt we will be seeing plenty more of him long after Williams has retired.