Tatsuya Imai — 2026 Season

2026 Season Highlights

As of September 1, Tatsuya Imai remains a fixture in the Houston Astros' starting rotation. He has picked up his share of wins since his Opening Day debut in the majors, though his outings have been inconsistent when it comes to limiting runs. His swing-and-miss stuff continues to show up, often playing a decisive role in how his starts turn out. Drawing on his track record as an ace in Japan, he continues working to fully adapt to major league hitters.

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.

• 1Imai has continued to take his turn in the Astros' rotation this season, racking up wins while also going through outings where runs have piled up, making for an up-and-down year overall.
• 2He arrives in the majors on the back of a strong track record in Japan, having won the NPB strikeout title in 2024 and posted a career-best ERA in 2025 as the ace of the Saitama Seibu Lions.
• 3Having held a rotation spot since Opening Day, the key storyline going forward is whether his performance can find more consistency down the stretch.