In two weeks, barring injury or earthquake, Rafael Nadal will hoist La Coupe des Mousquetaires, the French Open trophy. It is a fool’s errand to predict anything in sports, but you’d be a fool to bet against this. Nadal’s record at Roland Garros is 79–2; one of those two losses occurred nine years ago. Last year, he won his tenth French Open title. Along the way, he did not lose a set. This clay season, Nadal has looked dominant. It is, of course, possible that he will be beaten at Roland Garros; it is also possible that it will snow in Paris this week.

All this speaks to his current form, but it also says something about his current competition. With Roger Federer ceding the stage during the clay season, as is now his habit, Nadal has no real rival. Andy Murray is out with a bad hip, and Stan Wawrinka is struggling through a comeback from a knee injury. The biggest threat comes from Alexander Zverev, a lanky German with a big serve and a smooth swagger, who was up a break in the third set against Nadal in the Rome final before a rain delay dissolved his game. When the sky cleared, Nadal won five straight games—and the set, match, and title. Zverev, twenty-one, has been spectacular this spring, winning two straight titles before nearly taking Rome, but he has never made it past the fourth round of a major, and is 0–7 against top-fifty players at Grand Slams. Another challenge could come from Dominic Thiem, whose heavy topspin groundstrokes can kick off the dirt nearly as nastily as Nadal’s. Thiem knocked out Nadal in Madrid earlier this month and, last year, beat him in Rome, bookending Nadal’s winning streak of fifty straight sets. But Thiem only sporadically summons the inspired play that Nadal brings from match to match; until beating Nadal, the Austrian had not defeated a top-ten player all year.

There are other contenders, but each comes with a question mark. The Japanese star Kei Nishikori, for instance, has had a solid clay-court season, but it has been only four months since he lost in the first round of a lower-level ATP Tour Challenger event while coming back from an injury. The Belgian David Goffin is in good form, but his build is so slight that the jet wash from a Nadal backhand might blow him over. He recently told the Times that his original goal was to make the top hundred.

Then there is Novak Djokovic.

It was only two years ago that Djokovic held all the major titles and appeared almost unbeatable; only two years since he reached the final in twenty-one of twenty-two consecutive big tournaments (majors, Masters, and World Tour Finals), winning seventeen of them. Back then, he had played patiently and with purpose, pulling players out of position, hitting close to the lines, goading opponents to go for too much, and hardly ever missing his own mark. Sustaining such dominance—to a degree unmatched even by Federer or Nadal—had seemed impossible. And, in the end, of course, it was.

When Djokovic lost to the big-serving American Sam Querrey in the quarter-finals of Wimbledon, in 2016, after an exhausting, emotional victory at the French Open, it seemed understandable, perhaps even inevitable. No one could win so much for so long. But no one saw what was coming next.

There was a problem with his elbow, vague allusions to private personal issues, talk of shifting priorities. “Now I’m no longer thinking about the number of titles,” he said later that year, after losing the U.S. Open final. “If they come, super, I will accept them . . . After all, tennis is not the only thing in the world.” Indeed not. But when the titles did not come, that seemed harder to accept than he had suggested. He split with his coach, Boris Becker. He started working with a spiritual adviser, Pepe Imaz, and spoke about telepathy, telekinesis, and the power of hugs. He fired his whole coaching team (“shock therapy,” he called it), and then hired Andre Agassi, a move that was hailed at the time but clearly went wrong; their partnership ended this spring.

Whatever else was happening in his heart and mind, what was happening with Djokovic’s body was bad enough. His right elbow got worse and worse, and his serve, never his greatest strength, was obviously affected. He became less patient in constructing points, less efficient in reaching and returning the ball. His aggressive defense lost some of its punch. Eventually, the elbow injury became too much to play through. Djokovic sat the second half of 2017. When he came back, in January, his elbow still obviously bothered him, and, after a bad loss in Australia, he left the tour again for a “small medical intervention.” Once commonly described as a machine, Djokovic appeared to have broken down.

Finally, in Rome, Djokovic showed some of his old form—and some of his former fire. In a scintillating victory over Nishikori, he stepped into his swings with purpose. He reached seemingly unreachable shots. He roared. Against Nadal, in the semifinals, he pushed Nadal hard before losing, 7–6 (4), 6–3. In the best point of the match, both men’s unparallelled strengths were on display. After Djokovic bunted the ball just over the net, Nadal raced to it and dug it out before it dropped dead, flicking it cross-court. Djokovic lunged and caught the ball behind him, blocking it up the line, and had the wherewithal to recover and volley away Nadal’s sharp reply. But the point that followed was just as telling: Djokovic hit a backhand down the line—the shot his game is built on—and sent it wide.

Some champions, including Nadal and Federer, seem born that way. Others can’t help but reveal the strenuous effort and incredible ambition it takes them to get there. Djokovic transformed himself from near-great to one of the all-time best by an extraordinary undertaking. He monitored the ingredients of every morsel he ingested and focussed on chewing to help his digestion. He stretched so much that he turned his ligaments into rubber bands. Over and over, he hit the ball two centimeters from the line. He sought guidance, signed autographs, smiled for every selfie. He wanted to be a champion, and he wanted to be seen as a champion. It was obvious that he wanted it badly. It is to his great credit that he succeeded. It is also, perhaps, why some found him hard to take. And it is why there has been a tragic quality to his struggling—not in the colloquial sense of that word, but in the classical one.

It is possible that Djokovic will play his way into shape in the two weeks of the French Open. There is no reason to assume that he cannot someday return to the top. Whether he wants to is another question. After all, tennis is not the only thing in the world. It is hard to look at Djokovic—always lean, now almost bony—and not wonder about what he might desire, and what it might cost.