Kei Nishikori, the No. 10 seed at the U.S. Open, says he does not know whether he is fit to play following surgery to remove a cyst in his right foot.

Nishikori withdrew from Masters events in Toronto and Cincinnati as a result. He has decided to play the U.S. Open. The 24-year-old said he "had doubts about my decision but I am going to take a chance."

"I haven't had match practice and I don`t know if I will be able to keep up when it comes to quick movement," Nishikori was quoted saying by the Kyodo news agency. "If the pain comes back on the day of the game I don't know if I will play."

Nishikori has had injury problems throughout the year. He experienced a back injury in Madrid where he was runner-up to Rafael Nadal, and returned to play the French Open, exiting in the first round.

Nishikori, who also fell in the first round of the 2013 U.S. Open, plays Wayne Odesnik to open his campaign.