WIMBLEDON, England—Is this going to become an annual mid-year ritual on the tennis calendar? For the second straight season, Rafael Nadal has scaled the heights in Paris only to plumb the depths two weeks later here in London. This time, though, the riches-to-rags progression feels like it has more definite long-term consequences.

Last year, Nadal’s loss to Lukas Rosol in the second round at Wimbledon was an earth-shaking upset, as well an epic five-set match. Today his defeat one round earlier, at the hands of the equally unheralded Steve Darcis in three less-than-epic sets (7-6 (4), 7-6 (8), 6-4), didn’t feel like much of a shock at all. In the 12 months since his exit to Rosol, we’ve become used to the idea that Nadal’s knees will always trouble him, and that he’s now vulnerable at Wimbledon, a tournament where, not so long ago, he reached five straight finals and won two titles.

We may also have to get used to the sight of Nadal’s opponents playing lights-out, no fear tennis against him here. Darcis, a 29-year-old Belgian ranked No. 135, who had lost 12 of his previous 18 matches at Grand Slams and who had a 1-3 career record at Wimbledon, played with even more confident abandon than Rosol did in 2012. A light 5’10”, Darcis seemed to fly across the court, and he relished his chances to dive on it. He attacked without hesitation, making it to the net 46 times, and hit 53 winners to Rafa’s 32. Darcis mentioned his use of his slice backhand as something Nadal “didn’t like.” For someone who was going big whenever possible, Darcis also went for long stretches with very few errors. There can’t be many players who are under six feet and have one-handed backhands who have beaten Rafa in the past. And when Darcis felt some nerves trying to close it out, he said, his serve was there to bail him out.

Afterward, this unassuming soldier in the ATP rank and file enjoyed his rare opportunity to command the big interview room at Wimbledon. Darcis, a permanent grin plastered across his face, said that he had wanted to start the match well, but that he had no serious expectations of victory. Asked what his first thought was when he saw that he had drawn Nadal in the first round, he said: “‘Shit.’”

Darcis said he could tell right away that Rafa was off, but that he didn't notice any specific trouble with his knees. I thought Nadal was slow and probably hurting. When he was asked if he had any physical problems afterward, Nadal made a characteristically terse deflection: “I think now is not the day to talk about these kind of things,” he said more than once.

Of course, Nadal didn’t say anything about his knees after the Rosol match last year, either, but he has since admitted that they were hurting him. We may see a similar evolution this time around. Nadal doesn’t want to sound like he’s making excuses by talking about an injury immediately after a loss.

“The opponent played well,” he said instead. “I had my chances, I didn’t make it. In grass is difficult to adapt yourself, to adapt your game when you don’t have the chance to play before. I didn’t have that chance this year, is tougher. I didn’t find my rhythm...At the end it is not a tragedy.”

Nadal said he had wanted to play a grass-court tune-up in Halle, but had to take time to recover from the clay season instead.

More revealing, and more troubling, was this exchange:

Q: Did you have any sign at practice in previous days that it was going to be a tough first round here?

Nadal: You were here on Saturday? I said is probably the toughest surface for me today, because I had to move, and I have to play in a lower position than in the rest of the surfaces. So that’s the real thing. I was not lying to nobody on Saturday.”

As you can probably tell from those last lines, Nadal was testy—he laughed sarcastically at questions and hung his head in frustration before answering others. You can see the reason for this frustration in his response above. Judging by that answer, and by what he said this weekend, either he can't move and play the way he likes on grass with so little preparation anymore, or the surface aggravates his knee problems more than it has in the past.

“I played much more than what I dreamed before here after the injury,” Nadal said of his winning years at Wimbledon. “So that’s a fantastic and very positive thing for me. I know the grass is a difficult surface for the way I need to play well here. Was not possible this year. I gonna try my best for the next couple of years.”

Couple of years? That’s about as pessimistic as I’ve heard Rafa sound about any aspect of his future in tennis. It may be just an immediate reaction to his defeat, but it does seem, after Rosol last year and Darcis this year, that Nadal isn’t going to be the same player he was on grass. Which is a shame, because what was perhaps most remarkable about his career was the way, unlike many of his countrymen before him, he embraced the challenge of grass and made winning Wimbledon his greatest goal. The close proximity in time between Paris and Wimbledon once helped him bring his clay-court confidence across the Channel. Now the turnaround is too fast.

What was more sobering this afternoon was the way Nadal approached certain crucial moments, especially in the second-set tiebreaker. He served for that set, and had a set point in the breaker, yet his usual stubborn refusal to give in wasn’t evident. He said he never found his rhythm today, and that was true. But I can only guess that he also didn’t believe he had a chance of winning the tournament, whatever the result of this match was.

Nadal said that he’s confident he’ll have a “good recover” and be back on tour “not very late." He said he didn’t regret his heavy schedule of play over the last five months.

“I cannot say when I do a calendar if it was wrong or if it was positive,” he said. “Since six hours ago, was a perfect calendar, now is a very negative calendar? That’s not true.”

Today may have been another sign of his tennis mortality, at least as far as grass goes; but as he says, just this past January many of us were wondering if he would ever be the same player. Since then he's had the best five-month stretch of his career. He’ll take his wins when he can and rest when he must.

“This is a sport of victories,” was Nadal’s philosophical conclusion after this briefest Wimbledon, and briefest Grand Slam. “It’s not a sport of loss. Nobody remembers the losses. People remember the victories.”

The victor today was Steve Darcis, and as Nadal said, he “played fantastic,” shot-maker's tennis to do it. Nobody gave it to him, and he could have easily folded when four set points passed him by in the second set.

Darcis says he wants to get a “DVD of the match to keep at home.” Nadal says that people only remember the victories; it’s safe to say Darcis will remember this one.

“I think a lot of people will talk about this match in a few years," Darcis said. Then he added, his grin widening just a little, that he's looking forward to being one of them.