It has not been a pleasant period for Juan Martin del Potro following his maiden Grand Slam victory at this year's US Open.

ATP World Tour Finals tickets still available – click here

The 21-year-old has become one of the many injury-affected victims in a lengthy tennis season that shows no signs of slowing down.

Since his remarkable victory against Roger Federer in the US Open final in September, Del Potro has performed well below par. He lost in the first round of the Japan Open to world No.189 Édouard Roger-Vasselin in straight sets.

The Argentinian followed up that performance with a lean showing against Austrian Jurgen Melzer in the second round at Shanghai, retiring while trailing 5–7 1–2.

Del Potro has not been spotted on the ATP circuit since, preferring to rest in time for a major assault on the upcoming Masters tournaments in Paris and London.

Indeed, it is not the first time this year that he has decided to recharge his batteries following a busy playing schedule.

At the start of the US Open summer, Del Potro managed to defend his Washington title and also progressed to his first Masters 1000 final against Andy Murray in Montreal a week later.

Despite going hit for hit against the Brit in the opening two sets in Montreal, Del Potro eventually ran out of gas and succumbed to his rival 6-1 in the decider to hand Murray his second Masters title in 2009.

Citing fatigue, the world No.5 decided to pull out of the Cincinnati Masters in order to be at peak fitness for the US Open.

The decision proved a master stroke from Del Potro, who would go on and drop only two sets en route to making the final of his favourite Grand Slam.

Confronting a player who was after his sixth consecutive US Open title, Del Potro managed to cause one of the great upsets in tennis history, defeating Federer 3-6 7-6 4-6 7-6 6-2 to claim his maiden title at Flushing Meadows.

After just over four hours of competitive and vibrant tennis, the young Argentinian lay on the surface of Arthur Ashe arena, knowing he had finally realised a lifelong dream of winning a US Open title, defeating arguably the greatest player ever to wield a racket.

With the help of a devastating forehand that yielded 57 winners, he was able to limit Federer to a second placing at Flushing Meadows for the first time in more than 40 matches.

Having achieved his dream of winning the US Open, the will to be the world’s best player on the ATP circuit immediately transformed into Del Potro’s prime objective the moment he held aloft his maiden Grand Slam crown.

Although he has made his name the topic of intense discussion among tennis enthusiasts the world over, the road ahead for Del Potro is a long one in his bid to win more Slams and become world no.1.

He has yet to showcase the level of consistency that has made Federer, Rafael Nadal and Novak Djokovic certainties to reach the latter stages of Grand Slam tournaments.

What Del Potro has shown, however, is an uncanny ability to stand his ground against superior rivals, no matter what the circumstances.

He imposed his authoritative 198cm figure against Nadal in the US semi-finals, beating the Spaniard in a straight sets demolition.

Against Federer, Del Potro held his nerve, despite a shaky start, and backed his game to eventually turn around a match that saw the Swiss maestro relinquish his five-year dominance at Flushing Meadows.

Indeed, there is no doubt that Del Potro has the fighting qualities to battle it out for the No.1 spot in the ATP rankings.

Still in his early twenties, however, he has yet to master the ability of performing at his peak on a regular basis.

No doubt if Del Potro does train himself to play at the dominant level which saw him win his maiden Grand Slam title, then the sky is the limit for a player who really has the arsenal and mentality necessary to add significantly to his US Open triumph come 2010.

Buy ATP World Tour Finals tickets – November 22

Buy ATP World Tour Finals tickets – November 23

Buy ATP World Tour Finals tickets – November 24

Buy ATP World Tour Finals tickets – November 25

Buy ATP World Tour Finals tickets – November 26

Buy ATP World Tour Finals tickets – November 27

Buy ATP World Tour Finals tickets – November 28

Buy ATP World Tour Finals tickets – November 29