João Fonseca and the coach who has been saying the same thing for seven years

The point Fonseca will remember from his round-three win over Novak Djokovic at Roland Garros this fortnight was not the first set, which he lost 4-6, or the second, which he lost on the same scoreline. It was not the third or the fourth, which he won 6-3 and 7-5 to drag the match into a fifth and become the first teenager in thirty years of Grand Slam tennis to mount back-to-back two-set comebacks at a major, and the first teenager to beat a former men's champion from two sets down at Roland Garros since Michael Chang did it to Ivan Lendl on the way to the title in 1989. The point was the one near the end of the match: Fonseca serving for it at 6-5 in the fifth, break point down, three consecutive aces to close out the most significant win of his career to date.

You can describe those three aces in any number of registers. The technical register would talk about the ball-toss into the contact point, the racket-head speed on the first serve still firing untouched after nearly five hours of tennis on a heavy red clay. The psychological register would point to the absence of any visible adjustment in Fonseca's body language between the break point and the three serves that followed, which is a kind of even-temperedness most teenagers learn only after losing a major final or two. The third register, and the one the rest of this piece is in, is the coaching register. The three aces were the literal version of the sentence Guilherme Teixeira has been saying to João Fonseca, in some form or another, for seven years.

The sentence

"Maintain that aggressiveness. Continue doing that, but at the same time, let's work to be more solid." That is the instruction. Teixeira has been repeating it, with variations, since he first started coaching the twelve-year-old Fonseca at the Rio de Janeiro Country Club, and Fonseca, in interviews, has confirmed it almost verbatim: "I think my coach was really the first one that said: Keep with this aggression, keep doing this, but at the same time, let's work with being more solid." By the player's own account, that single instruction has been the through-line of his development.

The sentence does not sound complicated, and most coaching philosophies, in their actual articulation, are not. The complication lives in the work it requires the coach to do across years to keep the two halves of the sentence held together, because they pull against each other constantly: aggression unchecked produces unforced errors, while solidity over-applied produces a passive player who waits to lose. A player who can hold both simultaneously at nineteen years old, in the fifth set of a Grand Slam round three against a seven-time champion of this tournament, is unusual, and the coach who has spent seven years bringing him to that point is at least as unusual.

The coach

Guilherme Teixeira was born in 1987 and had a brief professional playing career that peaked at world No. 1,668 in doubles in 2006, when he was nineteen, before he stopped trying to be the player and started studying the coach. He saw Fonseca for the first time at the Country Club in Rio at a junior tournament where Teixeira was scouting the next round of young Brazilian players and Fonseca, at twelve, was one of them. The arrangement that followed, after Teixeira approached his parents, has now lasted seven years, which is unusual by tour standards: most professional tennis coaches turn over relationships every two or three years, sometimes more frequently when results stall, and Teixeira and Fonseca have not so much as taken a meaningful break.

Fonseca calls him a second father. The most-quoted line Teixeira has offered about the relationship is the horizon he has named for it out loud, in an interview: "We are preparing to be on the tour for the next fifteen years." A coach who names a fifteen-year horizon out loud is either talking the long game on purpose because the player needs to hear it, or because he actually believes it, and Teixeira, by every available account, means both at once.

What the coach has actually done

Fonseca's second serve is, for a nineteen-year-old, unusually penetrating and unusually consistent, and although there is no documented public technical change Teixeira has imposed on it, the durability of the motion across a 4h53m five-setter against Djokovic is the kind of durability that does not happen by accident. Coaches who train a serve to hold up over nearly five hours have spent years grooving it rather than weeks, and the result of that grooving, against Djokovic, was three first-serve aces in three deliveries at break point down in the deciding game.

The forehand under pressure is harder to argue with as evidence of coaching. Fonseca hit 30 forehand winners across sets three, four and five against Djokovic, and a teenager who can hit 30 forehand winners across the closing three sets of a Slam match against a former champion is a teenager whose forehand has been deliberately trained to fire under load rather than retract into safety. That is the "maintain that aggression" half of the seed line, visible as a stat line.

The mental work is harder to point at because it does not appear in the box score. The most-quoted intervention Teixeira has made on this front is concrete and slightly anachronistic: he told Fonseca to put the phone down and read books. The instruction is one a thousand coaches give to a thousand teenage athletes, but the difference is that this one appears to have taken. Fonseca, in his own words this May, said the thing every coach hopes the player will eventually say: "I can improve technically, but above all mentally." That is a teenager who has been told something useful enough times that he has started saying it back to himself.

The most recent piece of the work is the addition of Franco Davin, the Argentine who coached Juan Martín del Potro to the 2009 US Open. In March 2025 the team brought Davin in as a paid consultant focused on tactics and the big-event preparation that becomes everything in the second week of a major; he had been working pro bono with the team through 2024, and the arrangement formalised exactly when Fonseca's results moved from "the next Brazilian" to "world top fifty". Teixeira remains the lead coach, the second father, the holder of the seed line, while Davin is the consultant brought in for the bigger questions that arise when the player is in the third round of Roland Garros against Djokovic and someone needs to have thought about the third-set shift before the third set arrives.

The Djokovic match, as a coaching object

Coaching, when it shows up in a match, shows up at the joints rather than in the strokes, because the strokes were trained years before the match while the joints are negotiated on the day. What the player does at the joint between losing a set and starting the next one, at the joint between facing a break point and playing it, at the joint between exhaustion and the next deuce, is where the work of the previous years gets converted into the result of the current evening. Fonseca losing the first set 4-6 against Djokovic, after going up early, would have been the joint at which a different coaching template might have produced retreat, and losing the second 4-6 against a player of Djokovic's experience would have been the next joint at which a different template might have produced collapse. Fonseca instead came out for the third set hitting forehands harder than he had in the first two and then started constructing more carefully when leading, holding the two halves of the seed line together within the same match. By the fifth set he was the more believable player on the court, against an opponent who had been the more believable player on a tennis court for nearly two decades, and Djokovic said as much afterwards: "He without a doubt was a better player in important moments." Important moments, for a nineteen-year-old who has been coached well for long enough, are where the coaching does its work.

The limits, named honestly

Fonseca did not win the tournament. He beat Casper Ruud in the fourth round and then lost his quarter-final to Jakub Mensik 6-4, 6-3, 7-6(3) saving six match points in the deciding tie-break before losing on the seventh. The version of him who can save six match points and the version who loses on the seventh are the same player, and the coaching template still has work to do at the very top end. A quarter-final run is not a title, and a nineteen-year-old's first major quarter-final is some distance from a major final, which is why Teixeira's fifteen-year horizon is fifteen years for a reason. The player who eventually walks onto Philippe-Chatrier or Centre Court for a Grand Slam final will be a player who has had several more rounds of the seed line applied to him in match contexts more severe than this 2026 Roland Garros.

The Brazilian arc

The last Brazilian man to win a Grand Slam was Gustavo Kuerten, who took his three Roland Garros titles in 1997, 2000 and 2001, and Fonseca's quarter-final run at Roland Garros 2026 is the deepest result by a Brazilian man at a major in roughly twenty-five years. Kuerten was in the front row for Fonseca's last two RG matches, having watched the Djokovic match from Florianópolis Airport, and although he did not say much in public during the fortnight, the image of him in the box was the thing the Brazilian press wanted: the visible line from one generation to the next being drawn in real time. The line is being drawn, though, by neither Kuerten nor Fonseca but by Teixeira, a coach who has been holding the seed line steady for seven years in a country whose tennis system had not produced a Slam quarter-finalist for the entire span of his coaching career before this French Open. The next decade of Brazilian tennis depends substantially on Teixeira not pivoting away from the sentence he has been repeating since the player was twelve, and on Fonseca not asking him to.

What this means for a club player

The same question applies to a player who is not on the tour. What Teixeira did for Fonseca was not to give him a generic instruction. It was to identify what kind of player Fonseca was, aggressive by instinct and needing solidity on top, and then to keep saying that specific sentence to him, in some form, for seven years. A different player would have needed a different sentence. The coaching that improves a player at any level is the coaching that has identified the sentence specific to them and keeps repeating it. Most amateur coaches teach generic templates and change them every six months. If your own coach has not yet named your version of the seed line, that is the next conversation to have with them. If they have, stay with them long enough for the sentence to compound.

If you want a touring pro to watch you play and tell you the one sentence about your game worth repeating for the next year, the All Court waitlist is the way in. Access is being released in batches, and what comes back when your turn arrives will be specific, in writing, from a player who has earned the right to say it.

What the three aces Fonseca hit against Djokovic were really worth, beyond the win they produced, is the visible result of seven years of one sentence held steady by one coach. The serves were the receipt rather than the work, because the work had been done long before. The same long arithmetic is what produces visible improvement in any player coached well over time, at any level of the game, and there is no other arithmetic that produces it.