Watanabe, 37, has spent his entire 13-year career (2001-13) with the Chiba Lotte Marines in Japan's Nippon Professional Baseball league. Primarily a starter, the submarine-style pitcher has posted a career record of 87-82 with a 3.65 ERA (640 ER/1578.1 IP), and 846 strikeouts in 255 games (240 starts).
This past season Watanabe went 0-4 with a 4.62 ERA (13 ER/25.1 IP) in six games, all starts for Chiba Lotte.
A two-time NPB All-Star in 2004 and 2005, Watanabe was Chiba Lotte's fourth selection in the 2000 draft, and made his NPB debut on April 25, 2001. He pitched on both of Japan's World Baseball Classic championship teams in 2006 and 2009.
In addition, the Red Sox agreed today to release the contract of right-handed pitcher Chris Carpenter to the Yakult Swallows of the Nippon Professional Baseball league in exchange for cash.
The 27-year-old was a non-roster invitee to Red Sox spring training in 2013 and spent the majority of the year at Triple-A Pawtucket where he went 0-2 with a 4.96 ERA (25 ER/45.1 IP) and 48 strikeouts in 30 games (one start). For his major league career, he is 1-0 with a 5.17 ERA (9 ER/15.2 IP) and 10 strikeouts in 18 games between the Chicago Cubs (2011) and Red Sox (2012). Originally a third-round selection of the Cubs in the 2008 June Draft, Carpenter was acquired by Boston along with right-handed pitcher Aaron Kurcz in exchange for infielder Jair Bogaerts on February 21, 2012.