OpinionTime the one foe Nadal can't beat

There is nothing that arouses the senses of a sports fan like an indomitable force of nature. The freakishly talented are generational and if we are blessed to see three or four in our lifetime we should be truly grateful. In this generation there has been no athlete as dominant as Rafael Nadal on the red clay of Paris. No one even close.

Eight years ago a Spanish kid celebrating his 19th birthday and playing in his first French Open beat the imperious and top seeded Roger Federer in the semi-finals of the French Open. Two days later in the final he beat Mariano Puerta of Argentina. Coming into this year's event, Nadal had a 52-1 record in Paris with the sole blemish being a loss in the semis to Robin Soderling in 2009.

In eight years he has lost a grand total of 14 sets while winning seven championships. He is now acknowledged as one of the greatest players yet. Take away his seven French titles and he has two victories at Wimbledon, one in the US Open and one more in Australia. That alone would certainly qualify as a memorable career. But legendary? Not without his mastery on clay.

There is, however, one foe Nadal cannot dominate any more, not even on clay, and that is Father Time. Nadal will turn 27 tomorrow, so it would seem he has at least two or three more productive years left. And while they may be productive, they most likely will not be dominant.

He came into this year's event as the number four-ranked player in the world, which is hardly surprising considering he went seven months without playing. In his last grand slam appearance he lost in the second round of Wimbledon and was a no-show for both the 2012 US Open and this year's Australian Open. He has had serious problems with his knees and pulled out of the Australian Open with a stomach virus. In his first match last week he struggled mightily against German Daniel Brands, losing the first set and trailing in a second set tiebreak 3-0 before righting the ship and pulling away. He dropped the first set in the next round, too, before seeing off Martin Klizan of Slovakia. Last night, he advanced to the fourth round without dropping a set against Italian Fabio Fognini 7-6 (7-5), 6-4, 6-4. But when you lose only 14 sets in eight years, even the slightest imperfection is significant.

Ironically, Nadal's success on clay is also a large reason for his physical breakdowns. Unlike the speedier grass and hard-court surfaces, clay requires brute strength and there is no one stronger than Nadal. His sculpted and cartoonish physique has never really been seen in tennis before. And while he has lost some size over the past few years, he still looks more like a rugby player than a tennis star. His brand of play has been physical and punishing and it's a style that is not conducive to long career.