The 42-year-old right-handed closer helped the Boston Red Sox win the World Series in 2013 when he was named MVP of the American League Championship Series. He spent nine seasons in MLB, compiling 95 saves and a 2.66 ERA.
Prior to going to the U.S., Uehara was a member of the Giants from 1999-2008 and was a two-time winner of the Sawamura Award, Japan’s version of the Cy Young Award.
Last season, Uehara pitched in 49 games for the Chicago Cubs, winning three, losing four and saving two with a 3.98 ERA. He did not appear in the postseason and was released after the season.
In addition to Boston and Chicago, he also played for Baltimore and Texas.
The Giants are Japan’s oldest professional team but have struggled recently, finishing fourth last season in the Central League.