Rafael Nadal will never again reach the dizzying heights of his 2010 season.
That year, Nadal won every Grand Slam with the exception of the Australian Open. At the end of the season, he was the unquestioned No. 1 player in the world.
The following year, although he won his sixth French Open, he ceded the title of best player in the world to Novak Djokovic.
While Nadal won the 2012 French Open, it has been a rough year for the Spaniard. When Nadal was felled by Lukas Rosol in the second round at Wimbledon, tennis fans knew something was wrong with him.
He had to bow out of the U.S. Open because of issues with his knees, and Nadal has since failed to get back on the court.
Although, a plan for his return is in the works.
Nadal has announced his goal of returning at the 2013 Australian Open.
Even with a few tune-up tournaments, he faces a real struggle down under. Hard courts have never been kind to Nadal, having won only once each at the respective hard-court Grand Slams. And it's no guarantee that he'll be anywhere near his peak.
The rest of the year also looks like an uphill battle.
To those who have followed Nadal over the years, knee problems were something expected to catch up with Nadal sooner or later. It has never been to the extent that was seen last year, but his knees have always been a bit of a nagging issue for him.
For any tennis player, knee problems would be a serious hindrance. But for Nadal, it could mean the beginning of the end.
26 years old is when most other athletes are at their peak. In tennis terms, though, 26 is an advanced age, considering players are considered done when they hit 30.
Nobody relies more on his physical superiority than Nadal. If he loses that, then he becomes a much more vulnerable player.
Of course he didn't win and become one of the all-time greats simply because of his physical ability.
However, his incredible stamina and speed allowed him to get to seemingly untouchable shots and run around a ball to hit a forehand shot, rather than his much weaker backhand.
He could try and play a different style, but that could take months, or even years for him to finely tune.
Regaining the No. 1 ranking will require success across the entire year. It's the kind of sustained success that Nadal can't reach anymore.
If he wants to try and win Grand Slams, he'll likely have to play a lighter schedule, which means less tournaments. Unless he does great at every Grand Slam, he won't have the same kind of evidence in his favor for the top spot as Djokovic, Andy Murray or Roger Federer.
Nadal can be a very good player again, but he'll never be the best.