WASHINGTON, DC - AUGUST 05: Kei Nishikori of Japan competes with Alexander Zverev of Germany at William H.G. FitzGerald Tennis Center on August 5, 2017 in Washington, DC. (Photo by Tasos Katopodis/Getty Images)

World No.9 Kei Nishikori is the latest player on the ATP tour to pull the pin on the remainder of the season due to injury.

Nishikori joins Novak Djokovic and Andy Murray as players who have called a premature end to the year through injury.

The 27-year-old suffered a tear in one of the tendons in his wrist while training in Cincinnati prior to the Western and Southern Open.

“Two days ago during practice in Cincinnati, Kei hit a serve and heard a ‘pop' in his wrist,” a statement from Nishikori's camp read.

“We went straight to the hospital to take an MRI.

“Yesterday, we went to see a very renowned wrist specialist who works with many of the Major League Baseball pitchers. We saw another specialist today to get a second opinion. On top of that we have sent MRI results to three other wrist specialists to ensure we get several independent opinions.

“After consulting with all of them, it has become clear that Kei has a tear in one of the tendons in the right wrist. At this stage we have elected not to do surgery and Kei is in a cast.

“After the swelling comes down in the next weeks, we will evaluate the next steps. Kei will withdraw from all the 2017 tournaments and work hard to be ready for next year.”

Nishikori is also the fourth top-10 player to withdraw from this month's US Open, with Djokovic, Murray and Stan Wawrinka all set to miss the final grand slam of the year.