Inside The Mariners

Highlighting Hisashi Iwakuma's Career with the Seattle Mariners

In honor of the two-game Tokyo Series between the Los Angeles Dodgers and Chicago Cubs, we are looking at the contributions of several Japanese players to the Mariners franchise.
Seattle Mariners pitcher Hisashi Iwakuma throws during a game against the Los Angeles Angels on May 3, 2017 at Safeco Field.
Seattle Mariners pitcher Hisashi Iwakuma throws during a game against the Los Angeles Angels on May 3, 2017 at Safeco Field. | Joe Nicholson-Imagn Images

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The Los Angeles Dodgers and Chicago Cubs wrapped up the season-opening Tokyo Series on Wednesday morning.

The 2025 iteration of the Tokyo Series featured some of the best Japanese-born players in the game today: Shota Imanaga, Yoshinobu Yamamoto, Roki Sasaki, Seiya Suzuki and Shohei Ohtani.

The Seattle Mariners competed in the 2019 version of the Tokyo Series against the Oakland Athletics. Ichiro Suzuki played in front of his countrymen for the last time during that series. He retired following the showcase.

Seattle has a history of great Japanese-born players, including Suzuki. All week long we are highlighting those Japanese-born players with the M's, and today? Right-handed pitcher Hisashi Iwakuma.

He debuted for the Mariners in 2012 after a 12-season career in Japan's Nippon Professional Baseball. He pitched for the Osaka Kinetsu Buffaloes from 2000-04 and the Tohoku Rakuten Golden Eagles from 2005-11. He was a three-time NPB All-Star, two-time Best Nine award winner and won NPB's version of the Cy Young, the Eiji Sawamura award, and the MVP in 2008.

When Iwakuma came stateside, he wasn't an immediate fixture in Seattle's starting rotation. He made 30 appearances in 2012 (16 starts) and had a 3.16 ERA with 101 strikeouts in 125.1 innings pitched. The next season, he was fully cemented as a starting pitcher.

He had a 2.66 ERA in 33 starts with 185 strikeouts in 219.2 innings pitched in 2013. He also made his lone All-Star appearance. During that season, he set a Mariners franchise record for the most starts without giving up an earned run (10). He also set a record for the best ERA by a pitcher through their first 16 starts of a season (2.26). Felix Hernandez broke that record the next season (2.24) and Bryan Woo took the top spot last year (2.05).

Seattle had been looking for a solid No. 2 behind Hernandez for the majority of his career, and it seemed like the organization found that in Iwakuma. But his body would soon start to give out.

Iwakuma was already 32 years-old when he threw his first pitch for the Mariners. He had over a decade of wear and tear on his arm from pitching in a professional league. And it started to show in 2014. Iwakuma made 28 appearances that season and his ERA increased to 3.52. He made just 20 starts in 2015 and his ERA increased again, albeit marginally, to 3.56. There were still flashes of brilliance from Iwakuma. He threw a no-hitter in a 3-0 win against the Baltimore Orioles on Aug. 12, 2015.

After 2015, Iwakuma had agreed to a three-year, $45 million deal with the Los Angeles Dodgers. But a physical raised concerns and the deal was nixed. He instead returned to Seattle on a one-year deal with a vesting option for 2017 and 2018.

Iwakuma pitched 33 games in 2016 but his ERA had ballooned to over 4.00 by that point. He made just six starts in 2017. He then signed a minor-league deal and made just two appearances in 2018. He returned to Japan and pitched the final season of his career with the Yomiuri Giants in 2019.

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