Kei Nishikori will undergo surgery on his right elbow on Tuesday to address a lingering injury that caused him to end his season early, his management company announced.The Japanese world No. 8 revealed last month the injury had been bothering him since the French Open and as a result was forced to skip the ATP Tour's Asian swing, including the Rakuten Japan Open which he has won twice.Nishikori said on Twitter last month that he had made "great progress" with the injury and was "close to being pain free," but said he would be taking "3-4 more weeks off without tennis" on the advice of his …READ FULL ARTICLE