Free agent Orix Buffaloes closer Yoshihisa Hirano is poised to sign a two-year deal with the Arizona Diamondbacks, an informed source said Friday.

The 33-year-old right-hander, who primarily throws a fastball and splitter, has saved 156 games for the Buffaloes in Japan's Pacific League since moving out of the rotation in 2010. Hirano was 3-7 with 29 saves and eight holds in 2017, when he posted a 2.67 ERA.

Hirano, who chose to play for Orix as a premium pre-draft signing in 2005, began his career as a starter. After his second season in 2007, detached cartilage was discovered in his pitching elbow but he opted not to have corrective surgery at season's end.

Instead of being ready to return from surgery during the 2008 season, when Orix reached the postseason for the first time since 1996, Hirano delayed surgery until the end of March and he missed the entire season.

Hirano, who played on the national team at the World Baseball Classic in March, won the best middle reliever award in 2011 and led the league with 40 saves in 2014.

Hirano is one of four Japanese pitchers who entered the offseason seeking a contract with a major league team. Slugging Nippon Ham Fighters ace Shohei Ohtani has already agreed to a minor league deal with the Los Angeles Angels.

Free agent Lotte Marines right-hander Hideaki Wakui and submarine right-hander Kazuhisa Makita, who is being posted by the Seibu Lions, are also on the market.