Kei Nishikori has had a year to forget after enduring through a horrid 2017 which saw him go titleless and fall out of the top-10. After a stellar 2016, the Japanese dealt with a couple of injury problems this year before finally giving in, ending his season in August to fully recover from his lingering right wrist issue. He ended the year as the 22nd-ranked player but will look to return stronger than ever next year.

Win-loss record: Disappointing year for the Japanese

Nishikori ended his season with a 30-13 (.698) win-loss record, his worst since 2013. Furthermore, for the first time in his career, he finished the year with a negative record in tiebreaks. 11 of his losses disappointingly came against players of a lower ranking, with his most notable losses coming on clay in Rio de Janeiro and Bueno Aires, falling to players outside the top-65.

Kei Nishikori in action during the Brisbane International, his first tournament of the year where he reached the final | Photo: Bradley Kanaris/Getty Images AsiaPac
Kei Nishikori in action during the Brisbane International, his first tournament of the year where he reached the final | Photo: Bradley Kanaris/Getty Images AsiaPac

High Points of season: Decent start to 2017 and good results on clay

Nishikori had the perfect start to the year every player would have wanted; reaching the final at the star-studded Brisbane International during the opening week of the season. The Japanese impressively defeated world number four Stan Wawrinka in straight sets for his first and only top-10 win of the year along the way.

Being ranked fifth in the world at that point in time, Nishikori seemed poised to enjoy a successful year after having a decent campaign at the Australian Open, storming to the fourth-round where he fell to the eventual champion Roger Federer in five tough sets.

Kei Nishikori fell to eventual champion Roger Federer in a hard-fought five-setter | Photo: Clive Brunskill/Getty Images AsiaPac
Kei Nishikori fell to eventual champion Roger Federer in a hard-fought five-setter | Photo: Clive Brunskill/Getty Images AsiaPac

Nishikori experienced a decent North American hardcourt swing, reaching the quarterfinals at both the BNP Paribas Open and Miami Open. For the second consecutive year, the Japanese reached the quarterfinals in Indian Wells without losing a set. Another impressive week in Miami followed, but his injury nightmares came back to haunt him there, with a lower back issue causing him to fall in the last eight.

For just the second time in his career, Nishikori was able to progress to the quarterfinals of Roland Garros, clinching excellent wins over quality players like Thanasi Kokkinakis, Jeremy Chardy, Hyeon Chung and Fernando Verdasco in the process. His run surprisingly ended in the hands of world number one Andy Murray, who prevailed from a set down despite being plagued by an injury issue as well.

It was a decent run to the quarterfinals of Roland Garros for Kei Nishikori | Photo: Julian Finney/Getty Images Europe
It was a decent run to the quarterfinals of Roland Garros for Kei Nishikori | Photo: Julian Finney/Getty Images Europe

The Citi Open saw Nishikori clinch his last wins of the year, with the Japanese storming to the semifinals before falling to eventual champion Alexander Zverev. Nonetheless, he managed to rattle off some great victories along the way, triumphing over two home players and a formidable opponent in Juan Martin del Potro.

Low Points of season: Injury struggles

Nishikori reached the final at the Argentina Open earlier in the year but failed to hoist the trophy despite being the overwhelming favorite. The Japanese surprisingly fell to the unseeded 66th-ranked Alexandr Dolgopolov, being outclassed in straight sets. Things took a turn for the worse after he was shocked by Thomaz Bellucci just a couple of days after, crashing out in the opening round of the Rio Open.

Kei Nishikori would be disappointed with his poor loss in Rio | Photo: Buda Mendes/Getty Images South America
Kei Nishikori would be disappointed with his poor loss in Rio | Photo: Buda Mendes/Getty Images South America

He had decent results which followed, but the grass-court season could be considered poor by Nishikori’s standards. His lingering lower-back injury continued to bother him, forcing him to retire in his second-round match at the Halle Open. With a favorable draw, Nishikori missed out on a golden opportunity to progress deep at the Wimbledon Championships, losing to Roberto Bautista Agut in the third round.

In what could be one of the best matches in 2017, Nishikori blew a 7-6, 5-2 lead and also wasted a 6-2 lead in the final-set tiebreak, only to see Gael Monfils sneak out the incredible win in the opening round of the Coupe Rogers after a marathon and thrilling two-hours, 41-minutes. Unfortunately, this was also the last match of the season for the Japanese, who ended his season the week after due to a wrist injury.

Kei Nishikori would have rued the missed match points in his last match of the year against Monfils | Photo: Minas Panagiotakis/Getty Images North America
Kei Nishikori would have rued the missed match points in his last match of the year against Monfils | Photo: Minas Panagiotakis/Getty Images North America

Season Grade: C

Nishikori has been plagued by injuries for the majority of 2017, causing him to end his year much earlier than usual. This caused him to fall out of the top-10 for the first time in three years, and he will need to regain his form as quickly as possible, starting the new year as the world number 22, his lowest ranking since 2012.