Yoshihisa Hirano

The Diamondbacks have come to terms with Japanese righty closer Yoshihisa Hirano. In Japan, the 34-year-old accumulated 156 saves over his career, but he is probably just a back-of-the-bullpen arm for Arizona.Just a couple of seasons ago, Hirano was striking out more than 10 batters per nine innings in Japan, which would translate to a 9.0 K/9 in the majors. Last season, his K/9 dropped to 7.4 K/9, but he still posted a respectable 2.98 ERA. The strikeout drop, which would translate to 5.5 K/9 in the majors, is likely…