17 April 2026, Bavaria, Munich: Tennis: ATP Tour - Munich, Singles, Men, Quarterfinals. Fonseca (Brazil) - Shelton (USA). Joao Fonseca (Brazil) in action. Photo: Sven Hoppe/dpa (Photo by Sven Hoppe/picture alliance via Getty Images)

dpa/picture alliance via Getty Images

Joao Fonseca hears the buzz but blocks out the noise regarding his surging fandom. The Brazilian teen lets his management team, including his parents, mind the business, while he builds his portfolio on the court.

Fonseca begins his bid at the Internazionali BNL d’Italia Masters-1000 in Rome, today against Hamad Medjedovic. Fonseca is seeded No. 27, and the youngest player ranked in the Top 30. He’s had a solid clay-court season for far and feels good about his game.

“I think right now my game is in a great level…I’m healthy…and good mentally,” Fonseca said in an interview with Forbes.com.

Win or lose, Fonseca won’t assess his success or failure based on one match or tournament. The teen sensation seeks sustainable growth on and off the court. In a pre-tournament interview with ATP Tour staff, Fonseca talked about feeling more mature a year after his first appearance in Rome.

He credits his ability to focus, his on-court composure and maturity to having his parents and family friend managing his business affairs while he concentrates on improving his game.

Fonseca’s father, Christiano Fonseca, cofounded IP Capital Partners, a Brazilian hedge fund. His mother, Roberta, is a former athlete. Fonseca’s agent, Gustavo Abreu, is a long-time family friend.

Fonseca Family Business Model

Some of the best advice he got from his father, Fonseca heard and observed: pour yourself into work when you’re young so that you can enjoy life more when you’re older.

“My dad worked his whole life in the financial market. And, yeah, I think he worked a lot in the beginning of his career, and now he’s more like living the life,” Fonseca said.

Fonseca’s family is tight-knit and provides a fortress of well-being. They keep him calm and humble. When Fonseca won the Swiss Indoors Basel championship in October, 2025, he dedicated the title to his mother.

"My parents just came from Brazil. They were coming to Paris and changed their flights and came here one hour before the match with my uncles," Fonseca said during the trophy ceremony. "It is just amazing to have them here for the biggest title of my career."

Although both parents played sports, Fonseca’s parents leave tennis preparation to his son, the coaches and trainers. If Fonseca’s father weighs in on his game, he suggest taking the same attitude toward tennis as he does financial markets, incremental gains.

“When he was in his office, when I’m on my court, we try to do our best. I try to, every day, work one percent better,” Fonseca said. “He told me to focus on the little things that you don’t see every day, that you don’t make a result, like, quickly, but in the end, how can I say in, like, to the future.”

Fonseca is the youngest of three bothers. His brothers are 32 and 24. He believes having older siblings contributes to his maturity.

“I always try to be more mature. And this, I think, helped me,” Fonseca said. “They really helped to keep me grounded. . .We always talk, and they always help me on the little things.”

Fonseca entertained the idea of playing college tennis. Had he gone that route, he said he would have majored in business.

Learning To Play With The Pressure

Fonseca is weary of comparisons to the greats, including Brazilian legend Gustavo “Guga” Kuerten and Federer.

In a pre-tournament press conference, Fonseca told the ATP Tour staff, he’s learned to deal with the weight of expectations.

“I felt the pressure from people, all the expectations… I felt like everyone thought I was going to become the next Roger Federer almost overnight.. .But things don’t work like that. Now, I think I’ve understood that I only play for myself, that I don’t owe anything to people and that I don’t play for them, but for myself.”

Instead, Fonseca measures progress by steady improvement. That attitude is ideal for the clay court season. Clay rewards patience, construction, discipline, which mirror Fonseca’s mindset.

Fonseca’s Game: On Court And On Brand

As with any rising star in tennis, Fonseca attracted companies and agencies who wanted to hitch a ride on his soaring stardom. The behemoth brands came calling. However, in 2023, Fonseca signed a sponsorship deal with Swiss clothing brand, On, backed by Roger Federer, co-entrepreneur and early investor.

Federer’s investment in On, helped the 20-time Grand Slam champion join Forbes’s billionaire list. Although On was an emerging player in tennis, when Fonseca signed that deal, not many people in Brazil had heard of the brand. That didn’t matter to Fonseca who thought the partnership was a good fit.

“I was like, I’m going to go with On, like, doesn’t matter the money," Fonseca said he told his father. "It's a brand that I like. It was not very common in Brazil, like, only people that travel, like to US or Europe, had it.”

Now, On is more popular in Brazil, but Fonseca credits Federer.

Last year, during the Laver Cup in San Francisco, Fonseca met Federer for the first time and admitted he had sweaty palms.

When deciding which brands to sign with, Fonseca trusts his instincts and chooses to collaborate with companies that complement his persona.

“I if I like to represent this brand, if I think it’s a good brand, if I think it’s like a brand that really fits me," said Fonseca. ”There are some brands that I think are nice, but sometimes don’t fit me."

Federer’s management agency, Team8, approached Fonseca about signing. Fonseca decided to go with Abreu even thought he had never represented athletes. However, Abreu has a solid background in financial markets and most importantly, close ties to the Fonseca family, which was in no hurry to enter a long-term deal with a sports agency.

“He is a very smart guy, and we have a lot of confidence in him,” Fonseca said about Abreu. “We felt like he’s family, and he treated pretty me well, since I was a kid, as his kid."

Fonseca Opts For Authenticity In Age Of Hype

Few people understand the pressure Fonseca is under like Filipino star Alexandra Eala. When asked about comparisons to Fonseca, Eala echoed the Brazilian’s attitude toward managing the hype.

“The obligation first and foremost is to myself," Eala said in an interview with the Tennis Channel. "It’s my journey. I am really super grateful that all of these supporters want to follow in that journey that I have, but I owe it to myself first and foremost and to my family and team to give it everything that I have.”

Unlike Eala, Fonseca isn’t the first from his country to have major success in tennis. Kuerten won three French Open titles and reached No. 1. Still, Fonseca idolized Kuerten so much that the teen once tried a one-handed backhand. He ditched it, opting to play his game, explosive power off both wings. Staying true to himself is something Fonseca hopes to maintain on and off the court.

“When I’m trying to do something related to a brand, like commercially or whatever, (I) just try to be me,” Fonseca said. “I just try to not focus on, I mean, what people are saying, what people are talking and just try to be me and and be me is the most important thing.”