Perfect time for Nadal to take a break

The news that Rafael Nadal has decided to skip the U.S. Open because of the tendinitis in his knees rocked the tennis world a few days ago. The decision means that Nadal, the world's No. 3-ranked player, will have missed two of the five biggest events of the year, the Olympics and the U.S. Open.

However, if you're reconciled to the fact that, (A) Nadal's tendinitis can officially be defined as chronic and career-threatening, and (B) his results usually begin to tail off during the American hard-court season (and by the ATP World Tour Championships he's barely going through the motions), you can see how this is the perfect time for Nadal to take a break -- perhaps one lasting five whole months.

Let's face it: The hard courts at the Australian Open can also be tough on his knees. After all, the first sign of the tendinitis that prevented him from defending his 2009 Wimbledon title was the quarterfinal match he abandoned against Andy Murray at the 2010 Australian Open. But that tournament is at the beginning of the year, and there are not significant events leading up to it.

By contrast, the other hard-court major (the U.S. Open) is the climax of a six-plus-week North American tour, with all the tournaments on that most unforgiving of surfaces. And two of those events are Masters 1000s (the Canadian Open, which alternates between Toronto and Montreal, and Cincinnati).

Given the midsummer heat in the U.S., the run-up to the conclusion in New York can be brutal. It's also the last major on the calendar, and the top players have already done the heaviest lifting of the year (the nearly back-to-back majors in Paris and London). This makes the North American summer swing more taxing and contributes to the theory that the U.S. Open is the most punishing of all the majors.

Nadal's record in majors is weakest at the U.S. Open. He was 34-8 at the start of this year, compared to 29-6 in his next most challenging major, the Australian Open. Still, it might seem to make more sense for Rafa to suck it up and try to get through the U.S. Open, then abandon the fall tour altogether to rest his knees. That he chose not to do that is a pretty good indication of the severity of his condition -- and/or his concern for his future in the game.

Another intriguing factor in this mix is the state of Novak Djokovic's game. This spring, Nadal regained a good deal of the ground he surrendered to Djokovic in 2011, taking the measure of his Serbia rival in two Masters 1000 events (Monte Carlo and Rome). And Nadal capped off his resurgence by preventing Djokovic from accomplishing the first of his two stated goals for the year, subduing Djokovic in the final of the French Open.

Nadal's knees already were aching by the time the grass-court season started, even if his second-round loss at Wimbledon to Lukas Rosol of the Czech Republic rendered that issue irrelevant. But surely he watched with great interest as Roger Federer ended Djokovic's hopes for a successful defense of his Wimbledon title (and stripped him of the No. 1 ranking), and then Andy Murray stopped Djokovic from realizing his other major goal for 2012, a gold-medal performance at the Olympics.

Djokovic, who emerged through 2011 as genuine nemesis for Nadal, suddenly looks vulnerable. Given all this, Nadal might have gone into this upcoming U.S. Open in a better position vis-a-vis Djokovic than he's been in since the fall of 2010.

It must have taken a lot to convince Nadal to pull the plug on his quest to regain the last few bits of territory he surrendered to Djokovic in 2011. And when it comes to Federer, who is No. 1 again, well ... Nadal has been in a comfort zone against the Swiss champ for a long time now.

But with career longevity at stake, Nadal knows that Djokovic and Federer can wait.