It would be an understatement to say that Rafael Nadal has not been the picture of health over the last few months.
The last time we saw Rafa, he was walking off the court at the All-England Club with a hanging head after a shocking upset loss to Lukas Rosol in the second round at Wimbledon.
We all knew that something wasn't right with the world No. 3 during that match. He didn't look like himself, for if he was himself, he wouldn't have suffered a five-set loss to a man who, at the time, was the 100th-best player in tennis.
The tennis world's suspicions were confirmed when Nadal then pulled out of the London Games to rest his ailing knees. He was expected to carry the flag for Spain before his gold-medal defense began, but that obviously didn't happen, providing Andy Murray with a golden opportunity that he capitalized on.
They say bad things come in threes, and they certainly did in this instance.
Nadal recently withdrew from the US Open in Flushing, New York. He had this to say about his inability to participate (via Twitter):
I am very sad to announce that I am not ready to play the US Open in NY. Thanks to my fans for their support and specially, the new yorkers.— Rafa Nadal (@RafaelNadal) August 15, 2012
If the first two occurrences didn't frighten tennis fans, this most recent one surely should.
Rafa is one of the top-three players in the sport of tennis. Many tennis fans come to watch tournaments specifically to marvel at Nadal, Roger Federer and Novak Djokovic. To lose one-third of the three-headed monster would be a huge blow for tennis.
We don't know how long Nadal will be hindered by his balky knees, but tendinitis is a problem that tends to linger. It is a debilitating issue that has torn many top athletes down from the top of their respective sport.
At just 26 years old, Nadal's chronic knees problems and nearly three-month hiatus are a huge cause for concern. Tendinitis keeps an athlete from competing at the highest level, and Nadal is not the exception to the rule.
The fact that he's suffering from such a serious problem at a relatively young age would indicate that he isn't going to be around for as long as tennis fans would hope.
It could be a matter of years before we see Nadal become nothing more than a slightly above-average player—or worst yet, retire. That speaks volumes for his skills, but it is something that would be crippling to the sport of tennis.
Are Nadal's knee problems a huge cause for concern?
One day, probably sooner than later, Federer will relinquish his throne atop the world rankings. He won't be able to play at such a high level as he approaches the back end of his 30s and will one day retire.
If Nadal's knees keep him from being one of the best players, it could spell doom for tennis. Without Federer, there will be nobody to carry on a rivalry with Djokovic. There will be no more storylines, no more anticipating and hoping for a Nadal-Djokovic, Nadal-Federer or Djokovic-Federer final.
There will be other tennis greats to come after Nadal if he does in fact fade back into the shadows because of his knees, but there is no telling who will replace him down the road.
Nadal's problems are not just his, but tennis fans' problems as well.