When the Arizona Diamondbacks signed right-handed pitcher Yoshihisa Hirano to a two-year, $6 million contract this offseason, they did so knowing the 12-year veteran of Nippon Professional Baseball could be an effective reliever in MLB.

Yet the 34 year old “rookie” from Kyoto, Japan has surprised many with how quickly he has not only adapted to playing in the United States, but with how quickly has also become one of the most consistent relief pitchers in the National League.

Hirano currently has a 17-game, 14.2 inning scoreless streak that started on May 6. It is the third-longest active streak in the National League behind Jared Hughes of the Cincinnati Reds (18.1 innings) and Jon Lester for the Chicago Cubs (15.0 innings).

He has a 1.55 ERA in 29.0 innings pitched with 27 strikeouts and 10 walks. His current ERA, which ranks 9th for National League relievers, is a career low for him. He’s also 9th in the NL for Win Probability Added at 1.8.

He also has a great nickname in “Yoshi” that is a hit with baseball and video games fans alike, as well as the D-backs social media team.

On Monday, D-backs manager Torey Lovullo said he was “pleasantly surprised” with the start Hirano has got off to and by the success he’s having. Lovullo has been impressed with how quickly Hirano has adapted to playing in a different country.

“I thought there would be a little bit of a learning curve with a different sized ball, different mounds, different construction to the mound, but he plowed right through that,” Lovullo said. “I think he got over that in Spring Training.”

“What I’ve learned over the time that I’ve gotten to know him is that he is applying new concepts, he’s trusting the new coaches, and the new coaching that he’s getting. He’s trying to eliminate the language barrier and adapt to this culture, and he is now one of us. He is one of our teammates despite coming from another country, and that’s hard to do in the amount of time that he’s been here.”

Last season, Yoshi was 3-7 with 29 saves and a 2.67 ERA as the closer for the Orix Buffaloes, making a team-high 58 appearances out of the bullpen.

Hirano is one of only eight players born in Japan who are currently in MLB. He came into the league this year with Angels pitcher/designated hitter Shohei Ohtani, who is on the DL, and Kazuhisa Makita, currently playing for San Diego’s Triple-A team in El Paso.

With Hirano, Japan’s National Team won bronze in the 2017 World Baseball Classic. His 3.38 ERA in 5 1/3 innings of relief in the WBC, as well as the experience of playing in the U.S., paved the way for an opportunity to come to MLB.

His mid-90s fastball and forkball are his primary weapons, and both have been very effective this season.

“As far as stuff, it’s the execution of two different pitches in two different locations taking off in two different ways. And he knows exactly where that ball is going,” added Lovullo.

“Before Bracho got here, nobody else had the stuff that he had coming out of our bullpen, so it was a totally different look and he’s had a lot of success. But he’s making adjustments. He’s not just doing the same thing every single time.”

Hirano competed this spring for the closer role that was eventually awarded to Brad Boxberger. However, alongside Archie Bradley and Boxberger, Hirano has become part of what has been a formidable bullpen for Arizona that has the best ERA in the league at 2.55, is fourth in opponent batting average at .217, fifth in walks issued with 74, and ninth in wins at 37.

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