The news spread this week of Kei Nishikori signing two new lucrative sponsorship deals, one with his national airline (Japan Air) and the other a lifetime contract with tennis racquet supplier Wilson. This year saw the 25-year-old reach a career-high of number four and claim three ATP titles.
A convincing start to the season ended poorly as Nishikori was unable to replicate his success in comparison with the end of 2014, where he was a finalist at the US Open and semi-finalist at the ATP World Tour Finals.
Nishikori was the last to qualify for the World Tour Finals in 2015, finding himself in a round-robin group with Novak Djokovic, Roger Federer and Tomas Berdych.
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Beaten in straight sets by Djokovic, the eighth seed did manage to win one set off Federer before earning a consolation victory against Berdych of the Czech Republic.
His style of play causes many injuries. After missing the majority of the 2009 season due to elbow pain, Nishikori struggled once again in 2015.
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Hip injury and fatigue caused the 25-year-old to miss the Cincinnati Masters leading up to the US Open. The world number eight was then knocked out in the first round by Frenchman Benoit Paire.
His stature is also considered a weakness, being one of the smaller players on the tour. His serve is persistently put under pressure, winning just 55% of points on his second serve.
The world number eight has had success on clay this year, defending his title in Barcelona and reaching the final of the Mexican Open last February.
What does the future hold?
Having been backed by many - including Andre Agassi - working with former Grand Slam champion Michael Chang has shown great progression in his game. This year if he can he stay in top physical form and produce his best tennis again, he could potentially challenge for a Grand Slam and the Davis Cup with Japan's strongest team in years.
Nishikori is a beacon of hope for tennis in the far East; the first man in Asia to reach the final of a Grand Slam and qualify for the ATP World Tour finals. His returns and backhands are considered to rival the likes of Djokovic and Murray.
The 25 year-old's speed can trouble the top four players and his ability to dominate and dictate the tempo from the baseline forces opponents to play the style of tennis best suited to him.
With the majority of the season being played on hardcourt - Nishikori's best surface - can the world number eight look at 2016 to be his breakthrough season?
Do you think Nishikori can challenge the top four? Give YOUR opinion in the comment box below!