Tatsuya Imai — 2026 Season

2026 Season Highlights

As of 10/1, Tatsuya Imai is on the Astros' active roster and has pitched in both starting and relief roles this season. He continues to miss plenty of bats, but his walk total has been high and his ERA and WHIP have not been stable. A former Seibu Lions ace who led NPB in strikeouts in 2024 and posted a career-best ERA in 2025, he is still adjusting to life in the majors. He also took the ball as a starter on MLB Opening Day in 2026.

Tatsuya Imai (Houston Astros) was drafted first overall by the Seibu Lions in 2018 out of Sakushin Gakuin High School in Tochigi Prefecture. He overcame early shoulder injuries and emerged as a dominant ace from 2022 onward — winning the NPB strikeout title in 2024 and posting a career-best 1.92 ERA in 2025 before making the leap to MLB. 【Pitch Arsenal & Style】Imai works primarily off a mid-90s (150km/h+) four-seam fastball that touches 97 mph, paired with a sharp diving forkball (splitter family, ~85 mph with negative-vertical break) and a sweeping slider in the low-to-mid 80s. The fastball-forkball combination is built on tunneling: both pitches share a release point and arm speed before the forkball drops late, which is why opposing hitters chase below the zone at high rates. The forkball generates elite swing-and-miss rates — evidenced by 13 strikeouts in his first three MLB starts (K/9: ~13.5, swinging-strike rate above 14%). Walk prevention (11 BB in 8.2 IP, BB/9 ~11.4) remains the key area for improvement on his way to becoming a front-of-rotation arm. The Astros' development plan focuses on improving Zone% (in-zone pitch rate) without sacrificing the chase-inducing forkball usage. 【Team & Environment】The two-time World Series champion Astros (2017, 2022) are renowned for elite pitching development — turning Justin Verlander, Cristian Javier, Framber Valdez, and Luis García into front-line arms. Pitching coach Josh Miller and general manager Dana Brown have publicly emphasized command refinement as the next step for Imai. Minute Maid Park is pitcher-friendly with one of the AL's lower home run park factors. The retractable roof neutralizes weather variance — a comfort for a pitcher transitioning from NPB stadium conditions. Imai joins a rotation that has consistently ranked top-5 in starter ERA over the past five seasons, giving him strong pitch-mix and game-plan templates to absorb. His 2026 MLB stats — ERA, K, BB, K/9, BB/9, FIP, WHIP — are updated daily on this page after every start.

• 1His strikeout numbers stand out this season, but walks have been an issue and control remains a work in progress. That has weighed on his ERA and WHIP, and he has been struggling.
• 2His track record as a Seibu Lions ace is his foundation: he led NPB in strikeouts in 2024 and posted a career-best ERA in 2025. That swing-and-miss stuff has carried over to MLB this year.
• 3The key to watch is whether he can cut down on walks and settle his command. It will be interesting to see how far he can improve his results in the majors while keeping his strikeout ability as a weapon.