Mariners add Japanese pitcher Iwakuma to rotation Fri Jan 6, 2012 4:51pm EST (Reuters) - The Seattle Mariners have added starting pitcher Hisashi Iwakuma to their rotation and may audition Japanese infielder Munenori Kawasaki for a job during spring training, the Major League Baseball (MLB) team said. Iwakuma, one of the premier pitchers in Japan over the past decade, signed a one-year deal with the Mariners on Thursday. The 30-year-old will earn $1.5 million with another $3.4 million available in performance bonuses, MLB.com reported. "Seattle really wanted to get me," Iwakuma said through a translator in a conference call with reporters Thursday night. That was the most important thing. He signed with the Mariners a year after failing to reach a deal with the Oakland Athletics, who had paid a posting fee for the right to negotiate with him. Iwakuma is expected to slot into the third spot in the rotation behind Felix Hernandez and Michael Pineda. The right-hander was the Pacific League Most Valuable Player in 2008 when he went 21-4 with a 1.87 earned run average. He has a career mark of 107-69 in 226 games with Kintetsu and Rakuten. Health may be the biggest concern with Iwakuma, who was sidelined for two months last year with a sore shoulder. Kawasaki, who batted .267 with 161 hits in 144 games last season to help lead the Softbank Hawks to the Japan Series championship, told reporters in Japan he had been invited and planned to attend the Mariners' spring training camp in Arizona. Iwakuma and Kawasaki, 30, would be reunited with their World Baseball Classic team mate Ichiro Suzuki, a 10-time All-Star in 11 seasons with Seattle. The Mariners, whose principal owner is Hiroshi Yamauchi, the former chairman of Japanese-based Nintendo, open the 2012 MLB season with a two-game series at Tokyo Dome on March 28 and 29.