PARIS - MAY 26: Guillermo Coria of Argentina hits a backhand during the Men's Singles first round match against Tommy Robredo of Spain on day two of the French Open at Roland Garros on May 26, 2008 in Paris, France. (Photo by Mike Hewitt/Getty Images)

In life, there are those who work hard and those who don’t.

There are those who get lucky and those who don’t.

There are those who succeed where others fail.

In this sense, sport is a lot like life. Those who work the hardest reap the rewards, no matter how level the playing field may be. Others, for one reason or another, may simply get unlucky.

Here are six tennis players who, for one reason or another, did not fulfill the divine levels of talent they were gifted with.

Note: Only past players will be included on this list, meaning players such as Richard Gasquet and Ernests Gulbis will be spared…for now.

Guillermo Coria

Named for his compatriot Guillermo Vilas, Coria had similar levels of talent to the four-time Grand Slam champion, but a mix of doping, injury, psychological problems and even mental scarring contributed to one of the great lost tennis talents in the world.

The Argentine started off his career in a similar vein to Rafael Nadal – 7 clay titles and 4 finals between 2003 and 2004 saw him dubbed the ‘King of Clay’.

The epitome of this run culminated in Coria reaching the 2004 French Open Final, where despite being 2 sets to love up with a championship point, he lost in 5 sets to countryman Gaston Gaudio. To this day he remains the only man to lose a Grand Slam final from championship point. He was never the same after that match.

For the rest of his short career, Coria battled injury, marital problems, general loss of form and a bizarre case of service yips (Google it). He retired in 2009, aged just 27, citing the loss of desire to play the sport he once loved.

David Nalbandian

David Nalbandian is one of few men to ever reach at least the semi-finals in all four Grand Slams, and one of fewer in that category to have not won a slam.

One of the cleanest ball strikers on tour, Nalbandian played powerful, high percentage tennis, punctuated by a gorgeous two-handed backhand. His speed and brilliant tennis brain often helped him set up and put away points, often at the net.

It can be argued that Nalbandian achieved as much and got as far as he did on the tour on talent alone, but did not have the focus or work ethic of those that won slams off him.

In the end, injuries as well as his inability to work on his weaknesses, such as his serve and defence, cost him what could’ve been a potentially great career.

Mark Philippoussis

A name all Australia would likely be familiar with, Mark Philippoussis’ constant battle with injuries meant he had to be working his absolute hardest when on the court. Unfortunately, that was almost never the case.

During his time on the tour, he was widely regarded to have the poorest work ethic of the sports’ top players, and was commonly preoccupied by his socialite lifestyle, which included dating celebrities, filming tv shows and spending the seven million dollars he earned whilst on tour.

In 1998 he made the first of his two Grand Slam final appearances, beaten at the US Open by fellow Aussie Pat Rafter. Just over 10 years later he announced his bankruptcy.

The youngest man in the top-50 and a career-high ranking of world number #8 now seem like so long ago.

Marcelo Rios

Marcelo Rios is of the common breed of arrogant South Americans that when confronted with success cannot get out of their own way. He now lives on as the trivia answer to “the only player to be ranked world #1 and not have won a Grand Slam”.

Granted, Rios had his career cut short by a back injury aged 27 in 2004, but had not played since the 2003 French Open, when he retired in his first round match against Mario Ancic.

Yet it stands that Rios was his own number one problem. 18 career singles titles and one Grand Slam final in 1998 are often overshadowed by numerous and bizarre controversies, including speeding fines, running over his trainer with his car, urinating on a group of men during the Davis Cup, bar brawls, arrogant insulting of the Wimbledon tournament, mooning journalists and allegedly throwing his wife out of a moving car.

After achieving the number one ranking in 1998, an Argentine reporter asked him what it felt to be like on the same level as Argentinian champion Guillermo Vilas. Rios replied with "I've been compared to Vilas for a while now. I do not know him. All I know is that he was #2 and I’m #1."

In a brilliant turn of poetic justice, Vilas is still remembered as a champion; Rios, a despicable buffoon.

Marat Safin

The most talented man on this list, it is hard to call a former world number one and two-time Grand Slam champion an “unfulfilled talent”, but with Safin, we’ll make an exception.

Dubbed the future of tennis by the great Pete Sampras whom he destroyed to win his maiden Grand Slam in 2000, when put in perspective, it is disappointing that Safin was only able to add one more in 2005.

Generally, Safin’s attitude towards the sport was terrible. Not in the way that the others on this list was, but terrible in the fact that his on-court demeanor and attitude was rarely, if ever, at the level required to win Grand Slams.

Instead of winning majors, Safin became famous for self-imploding, losing interest mid-match, letting minor problems affect his game and of course, smashing rackets, of which he calculates he ruined 1,055 in his pro career.

Tennis critics and pundits say he had the talent to rival even Roger Federer, but injuries, mental weakness and inconsistency robbed of us a potentially great career.

Robin Soderling

Robin Soderling is on this list for a vastly different reason to all others. The Swede partners Novak Djokovic as the only two men to beat Rafael Nadal at the French Open, which alone speaks volumes.

In his time on the tour, Soderling reached a career-high of world #4, reached two consecutive French Open Finals and two further major quarterfinals at Wimbledon and the US Open.

With a huge forehand and service, which could reach speeds of 230km/h, he tactically developed his game under coach Thomas Muster to be equally as effective on unfavourable surfaces. It is this kind of personal improvement that earmarked Soderling as a future Grand Slam champion.

At the time of his third Swedish Open triumph in July 2011, he was ranked #5 in the world. A few weeks later, he contracted glandular fever. He never played tennis again.