Kei Nishikori had surgery on his right elbow at a hospital in Japan on Tuesday evening, his management company said.The 29-year-old Japanese tennis star is due to begin rehab on Thursday, return to full training in early December, and make his comeback next season, it said.Nishikori, who revealed he had "swelling and fluid in the elbow" since the May 26-June 9 French Open, announced Monday he would go under the knife.The No. 8-ranked player stepped away from the tour after making a third-round exit at the U.S. Open at the end of August, and missed the ATP's Asian swing, which includes the R…READ FULL ARTICLE