A problematic patella tendon had prevented Rafael Nadal from gracing any tennis court since the 2012 installment of Wimbledon.
So, when he withdrew from this year's Australian Open in January, there was genuine concern as to whether the Spaniard would ever return to the top level of the sport. He cited a stomach virus as the reason for his omission from Melbourne, but it did not stop tongues from wagging.
He did get his season underway in February, but not among the world's elite. Instead, Nadal embarked on the Golden Swing - a quartet of tournaments in South and Central America.
He reached the final of the VTR Open in Chile, but he lost out to world number 73 Horacio Zeballos. However, titles in Sao Paulo and Acapulco followed courtesy of success over David Nalbandian and fellow countryman David Ferrer.
Out of the comfort of the clay, Nadal returned to the bigger stage at Indian Wells as the number five seed. There he defeated his old sparring partner Roger Federer, before recovering from a one-set deficit to claim the title at the expense of Juan Martin del Potro.
A shock was in store during April's Monte Carlo Masters. Nadal, dubbed the 'King of Clay', went into the final as the eight-time defending champion, but he lost 6-2 7-6 for the first time since 2005 to Novak Djokovic.
Triumphs in Madrid and Rome eased the disappointment, though, which sent him into the French Open in positive form. He backed that up by knocking out Djokovic in the semi-finals at Roland Garros and then getting the better of Ferrer in the final - the eighth success in Paris in his career.
However, for the second year in succession, Wimbledon would be a tournament to forget. Twelve months earlier he was in obvious pain as Lukas Rosol won their second-round encounter and the same knee caused him problems as Belgium's Steve Darcis eased through in the opening round at SW19 this time around.
July came and went without a title, but back-to-back wins in Montreal and Cincinnati in August not only made him one of the favourites to win the upcoming US Open, but also saw Nadal close the gap on Djokovic at the top of the world rankings.
He would eventually get the better of the Serbian in the final at Flushing Meadows in four sets, which in turn saw him claim the 13th Grand Slam title of his career and a second in New York.
In terms of trophies, the tour of Asia in October proved not to be profitable, but his performance at the China Open - where he was defeated by Djokovic in the final - meant that he had replaced the 26-year-old as the world's number one player.
Nadal then ensured that he would take that status into 2014 with a 100% winning record in the group stages of the ATP World Tour Finals last week. Federer was then routinely beaten in the semi-finals, which somewhat fittingly set up a final against Djokovic.
There would no fairytale ending on this occasion, though, as Djokovic surprisingly eased to a 6-3 6-4 victory. Even so, many believe that Nadal can look back on the last few months as some of the best of his career. Vamos Rafa!