Rafael Nadal looks vulnerable

IT WAS JUST last year that Rafael Nadal was tearing through the competition, winning 10 titles (including the French Open and U.S. Open) and regaining the No. 1 ranking. Any talk of slippage was aimed at Roger Federer, he of the 30-plus years and the bad back, and Novak Djokovic, who hasn't won two majors in a year since 2011.

But as his favorite slam nears, suddenly Nadal is looking vulnerable again. Nadal, 27, has won the past four French Open trophies and eight of the past nine. But a series of shaky performances, lingering injuries to his knee and back, and a self-described "lack of confidence and competitiveness" in key moments have renewed the slippage conversation that began in 2012, when he dropped to No. 4 in the world.

Of course, Nadal's weaknesses never truly disappeared: the furious style that punishes him as much as his opponents, the doubt that hounds him until he breaks an opponent's serve for the first time and the ever-present specter of Djokovic, who is a better player overall. But as the surprising losses have piled up this year, the narrative has changed dramatically. Nadal may have been injured in the Australian Open final, but Stanislas Wawrinka also overpowered him. He's lost two of his past three matches to David Ferrer, whom Nadal has dominated for years; the last of those losses came on clay, Nadal's favorite surface, at Monte Carlo. As the defending champ at Indian Wells, he lost a third-round shocker to 31st-ranked Alexandr Dolgopolov.

Djokovic is still the player who exposes Nadal's flaws most effectively and, despite a recent injury of his own, presents his greatest obstacle. He's beaten Nadal in three straight meetings (all in finals), and Nadal has not shown in more than a year that his weapons are enough to prevail when Djokovic keeps his nerve. Only when matches are stripped down to slugfests has Nadal found a path to victory, as in last year's U.S. Open final. When facing Djokovic, Nadal must reach his most primal, desperate state for his ferocity and power to overcome his doubts. And it's happening less often: Not only has he lost to Djokovic those three straight times, he hasn't won a set, or more than four games in any set.

When Djokovic is uninjured and clearheaded, he is untroubled by the traits that make Nadal lethal to almost any other player: the high topspin to the backhand, the vicious inside-out crosscourt forehands and even the bottomless willpower. Djokovic has the talent and the patience to withstand Nadal's pressure, then overcome it with his superior backhand and serve and equally good forehand and defense.

The telltale sign of Nadal's vulnerability, especially against a superior player like Djokovic, is when his returns barely cross the service line and his hit point moves behind the baseline. From that position, unable to step forward and unleash, Nadal gets pushed off the court.

Psychological weakness is the great enemy of the focused athlete, and almost every elite player refuses to acknowledge its myriad symptoms: fear, doubt, nerves and anxiety. Nadal is the exception. He admits his vulnerabilities, telling reporters that even when he's winning easily, he's hyperaware of the tiny mistakes within each rally, always cognizant that defeat is closer than it appears. His openness serves as proof that even as he dominates his sport, he also is humbled by it.

Nadal poses a striking contrast to the traditional Federer, who is perpetually stoic in the face of injury and who, after losing to Djokovic at Indian Wells, dismissed concerns about his 32-year-old body by declaring that "age is just a number." He's wrong, of course -- in sports, age is the defining number -- but his defiance reflected a typical champion's mentality. Regardless of the optics, Nadal will always acknowledge when he is defeated by pain.

No matter where Nadal goes this year, he remains the glue that holds the sport together. He is at once underdog to Djokovic and charismatic foil to Federer, who had been peerless until Nadal arrived. He is both fan favorite and villain. (No athlete's injury history since Roberto Clemente's has annoyed fans as much as Nadal's.) He is a living reminder of the enormous physical cost of tennis and of the slim margin between victory and defeat.

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