Rafael Nadal reclaimed the No. 1 ranking in the world by beating Stanislas Wawrinka 7-6, 7-6 at the Barclays ATP World Tour Finals. It completed an impressive year which saw the Spaniard fight his way back from injury and climb to the pinnacle of tennis despite sitting out the calendar's first Grand Slam tournament.
At the tender age of 27, if Nadal can keep his creaky knees intact, he is poised to remain at No. 1 and enjoy a prosperous 2014 that is all but certain to include yet another title at Roland Garros.

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The only things that can hold Nadal back are his knees.
Nadal hit a bumpy road after capturing his seventh French Open title in June of 2012, when he beat Novak Djokovic and lost only one set during the entire tournament. Shortly after that, Nadal's bum knee reared its ugly head once again, leading to a shocking second-round loss at Wimbledon to Lukas Rosol. The knee tendonitis subsequently forced his withdrawal from the Olympics and the U.S. Open that year (per Associated Press, via ESPN).
Nadal falls to Rosol at Wimbledon in 2012.
Rafa's 2013 campaign began on the couch when he sat out the Australian Open with a stomach virus (per ESPN). Suddenly, it seemed that physical decline could decimate the clay-court specialist, as he fell from tennis' top-four rankings for the first time in eight years.
But Nadal allayed all fears with a convincing victory at the Indian Wells Masters in March, beating Roger Federer on his way to dispatching Juan Martin del Potro in the final. He won his sixth tournament of 2013 at May's Rome Masters over Federer and was clearly back in top-flight form following a disappointing end to 2012.
Rafa's signature victory of 2013 did not come in a tournament final but rather in the semis of the French Open. Nadal outlasted No. 1 ranked Djokovic in a thrilling match that required him to break Djoker in the fifth set for a gutsy 6-4, 3-6, 6-1, 6-7, 9-7 victory. Unlike 2012, Nadal showed no ill effects after beating Djokovic, and he took care of David Ferrer in the final.
Nadal bets Djokovic at 2013 French Open semifinal
He suffered a surprising hiccup against unseeded Steve Darcis in the first round at Wimbledon, but he flashed some prowess on the hard court with an impressive run to the U.S. Open title, beating Djokovic yet again, only this time in the finals.
Nadal currently sits at 13 Grand Slam titles—four behind 32-year-old Federer—and looks to be at the top of his game. He has demonstrated the ability to beat tennis' best players on hard courts, as well as on clay, and he could certainly make a run at Federer's mark. At any rate, Nadal will tie Pete Sampras with his next Grand Slam championship.

Nadal's poor showings recently on grass at the All-England Club are certainly cause for concern, but his recent potency on hard courts suggests he will be at the top of his game for quite some time to come. All he has to do is keep those knees healthy, so his coach should get him loaded up with CoQ10 and glucosamine.
The injury bug bit again recently when he cut the finger on his left hand (Rafa is a righty but hits tennis balls lefty) while slicing some bread for a snack (per Angel Rigueira of MundoDeportivo.com, in Spanish). At least it wasn't his knee and the cut was not serious, but someone please inform Rafa that his local panadero will gladly slice the loaf for him.
The best tennis player in the world should not have to make his own sandwiches. He must remain completely focused on continuing to dominate the sport in 2014 and holding off his chief competition in Djokovic. Nadal has already provided ample proof that he is capable of doing both those things.

Source: http://bleacherreport.com/articles/1842993-rafael-nadal-set-for-big-success-in-2014-after-a-stellar-comeback