Wim Fissette has had a front-row seat for World No.3 Naomi Osaka's rise over the last three years. Now he's been tasked to make sure it continues.

The 22-year-old brought on the veteran Belgian coach during the off-season and if her level during the first week of the season is any indication, Team Osaka has been able to build on the momentum she built to finish the 2019 season.

"I coached against her the last three, four years, with Angie at Wimbledon, with Vika in 2016 in Melbourne, also with Johanna Konta in 2017," Fissette told reporters at the Brisbane International. "I saw very good development the past years. Her movement got a lot better the past years.

"It’s very clear that she loves the big stages, the big moments. Even at 22, she puts her goals very high. That’s also interesting.

"I worked with many Top 10 players but there’s a big difference in ambition. You would expect it all to be the same but it’s not. I believe that Naomi is by far - not by far, Vika was very ambitious too - but Naomi, at her age especially, is super ambitious and has a lot of goals for her career."

Since bowing out of the US Open to Belinda Bencic in the Round of 16, Osaka has lost just one match, compiling a 14-1 record since. That lone loss came at the Brisbane International last week, where she failed to capitalize on a match point and lost to No.2 Karolina Pliskova in the semifinals.

"With a player like Naomi, you go to tournaments to win them, not to play finals or semifinals," Fissette told reporters at the Brisbane International. "That’s the ambition and I love that ambition. I love working under pressure. In general, I always feel like I worked better also under pressure.

"It’s not like we had to change a lot. I would have changed a lot had I started after the US Open. But she made a big change there, she went back to using her strengths better in the Asian swing and she got her winning game plan back."

"One of the goals was to perfect the serve a little bit, to improve a few percentages technically, to have a cleaner serve, a healthier serve. The serve is probably her biggest weapon, so that is always the biggest focus in training. You need to keep working on the biggest strength."

After struggling with a shoulder injury to end the 2019 season, Osaka's serve was clicking perfectly in Brisbane, where she set the record for most aces served in the tournament, firing 54 in four matches. In fact, Osaka set her personal best in back-to-back matches, firing 16 aces in her opening win over Maria Sakkari and 18 aces against Sofia Kenin.

"She’s different than I thought. She is, to me, a very intellectual player and person. She knows exactly what she’s doing and I think that helps her to be very cool at the most important moments."

Osaka said Fissette's experience and tactical knowledge one of the primary reasons for the hiring. "I think he's had a lot of experience with previous players," Osaka said. "I expected a lot of information, for him to know what he was talking about. Just being able to respect that I can trust him. I feel like it's been working out well, even though we've played one tournament together."

So far, Fissette has been impressed with how Osaka has been able to match his analytical tendencies.

"I’m maybe known as an analytical coach," Fissette said. "I love to use data and that’s what I did. I brought in data to analyze her and to see which were the keys to go to the next step and hopefully we’ll see the next weeks that we got that extra step."

"When I started with her I didn’t know how she was thinking in a match, was she just playing on intuition or was she really thinking and calculating?

"She’s different than I thought. She is, to me, a very intellectual player and person. She knows exactly what she’s doing and I think that helps her to be very cool at the most important moments. It’s like she calculated exactly what she needs to do to win matches, and I believe that helps her.

"So far, that’s my analysis after one month. That was a big surprise for me, the way she was calculating and stuff like that."

Naomi Osaka with new coach Wim Fissette (Jimmie48)

Osaka admitted on Saturday that she's been calculating more than just on-court percentages in Melbourne. As she readies for her title defense to kick off on Monday against talented Czech Marie Bouzkova, Osaka said the prospect of having to defend 2,000 points has been on her mind.

"I think I would drop out of the Top 10 if I lost in the first round," Osaka said. "That kind of weighs heavily on my mind, like, all the time at US Open and here. Just getting that out of the way and trusting myself and knowing if I play the best that I can, then obviously I won't lose in the first round.

"But, yeah, it's just like this constant. Negative 2,000 points is in my brain all the time. Trying to avoid that."

If that's the pressure on his charge, how is Fissette feeling?

"There’s no different pressure for myself," he said. "I want to coach players to win Grand Slams and that has always been the ambition and it’s still like that.

"Working with Naomi Osaka, the goal must be to become No.1 in the world again and to win a Grand Slam, more Slams.

"We’ll try to win every tournament we play and that should be the goal with a player of her level."