Nishikori gears up for potential defining year

Swashbuckling Japanese superstar Kei Nishikori has his sights set on not only a Grand Slam title but a further climb through the rankings as he gears up for what could be a defining year.

The 25-year-old has moved to a career-best No 5 in the world from 17 at the beginning of 2014 after a breakout season in which he won four titles and reached the US Open final, losing to Marin Cilic.

Only players of the caliber of Novak Djokovic, Roger Federer, Rafael Nadal and Stan Wawrinka stand ahead of him, a remarkable achievement for a player who has overcome barriers to make Asian tennis history.