WIMBLEDON, Great Britain - Patrick Mouratoglou hopes that Coco Gauff "doesn't realise how big she has become" at Wimbledon in the space of a few days, with the 15-year-old going from an almost-unknown qualifier to the new star of Centre Court. 

In an interview with wtatennis.com, the Frenchman disclosed he wouldn't be talking to Gauff about her new public profile in case it distracts her before she plays Simona Halep in the fourth round on Monday. Mouratoglou, who coaches Serena Williams, has also been working with Gauff at his academy in the south of France since she was 10 years old.

READ MORE: 'It's pretty surreal how life changes': Gauff halts Hercog, sets Halep battle at Wimbledon

"Coco was completely unknown when she came here, but now she's big, she's everywhere, and I don't want to talk to her about that," Mouratoglou said of Gauff, who saved two match points against Slovenia's Polona Hercog to become the youngest player since Jennifer Capriati in 1991 to reach the last 16 at the All England Club.

"Believe me, we're into the tournament and the only thing I don't want her to realise is how big she is. She shouldn't realise where she is, how big she has become - she just has to play, keep focused, and go as far as she can." 

Mouratoglou said the Wimbledon crowds already "love" Gauff's personality. 'When was the last time that you saw someone ranked around 300 in the world playing someone unseeded on Centre Court? But what she is doing is so incredible. And I also think people love her personality. I arrived just after the start of the match, so didn't see the first three games. I was there waiting to go in, but I knew when she was winning points and when she was losing points just by listening to the crowd." 

Mouratoglou is hugely impressed by Gauff's achievements but believes Serena is more likely to end the tournament as champion. "I love that Coco thinks she can win the tournament. I think that's great," he said. "Everything is possible in life. The chance of her winning the tournament is not big. There is always a chance when you believe and she believes. I think Serena is going to win." 

READ MORE: As It Happened: How 15-year-old Cori Gauff pulled off a Wimbledon miracle to make the Round of 16

It was Gauff's "refusal to lose", according to Mouratoglou, that enabled her to save two match points. "The thing that was amazing was when she was about to lose, when she was just one game from losing, I suddenly saw a light go on in her and she was playing at a different level because she was refusing to lose," he said. "And that is something that you see very rarely. You don't see that very often. That was amazing - that refusal to lose allowed her to win, twice coming from match point down." 

Serena Williams with coach Patrick Mouratoglou

Gauff is already playing as if she's in the Top 20, said Mouratoglou. "I'm not surprised at the level of tennis Coco is playing. Speaking more generally, I'm not that surprised by how she is playing because I've known her qualities since she was 10 years old. Perhaps I'm surprised that it has come so fast. She has broken so many records so far, so I shouldn't be that surprised that she has broken another one. 

"I expected her to win against Hercog. I didn't expect Hercog to play that well - I think she played at a great level. That made it much tougher for Coco. She had to dig really deep. She's playing a decent Top-20 level, and she's a great competitor so when it comes to the big points, in general she's there. The scenario of that match, though, with the match points, that was totally unbelievable."