Japanese ace tennis player Kei Nishikori will sit out the remainder of the season as he has ruptured a tendon in his right wrist, his management firm said Wednesday.Nishikori, ranked ninth in the world, withdrew Sunday from the ongoing Western and Southern Open, a tuneup to the U.S. Open starting late this month in New York, after experiencing pain in his right wrist during practice.The 27-year-old heard a popping sound in his wrist when he served during the training session in Cincinnati and rushed to a hospital where he underwent an MRI examination and also had it seen by several other sp…READ FULL ARTICLE