Star Japanese right-hander Tatsuya Imai has signed a three-year contract with the Houston Astros, the team announced Friday. The deal includes player opt outs after the 2026 and 2027 seasons, guarantees $54 million, and could be worth up to $63 million. Imai, 27, entered the posting system as one of the most intriguing pitchers on the market this winter, drawing comparisons to recent NPB standout Yoshinobu Yamamoto.
Imai has developed into an ace-level pitcher in Japan, earning three NPB All-Star selections, including honors in both 2024 and 2025. He has posted an ERA under 3.00 while striking out more than a batter per inning in each of the past three seasons, but 2025 marked the best year of his career. Pitching for the Seibu Lions, Imai went 10-5 with a career-best 1.92 ERA and 178 strikeouts across 163⅔ innings, and he was part of a combined no-hitter during the season.
Across eight seasons with Seibu, Imai compiled a 58-45 record with a 3.15 ERA and 907 strikeouts in 963⅔ innings. Since the start of the 2023 season, his ERA sits at an strong 2.18, and he has averaged 9.5 strikeouts per nine innings, reinforcing his reputation as one of the most dominant pitchers in Nippon Professional Baseball.
Imai features a power arsenal with a four-seam fastball and a slider. His fastball averaged 94.9 mph in 2025, slightly above the MLB average for right-handed starters, and can reach the upper 90s. His slider averaged 86.2 mph and generated a 46% swing-and-miss rate. He also relies on a changeup against left-handed hitters, averaging 85.5 mph with a 41% whiff rate, while mixing in a splitter, curveball, and a newly developed “Vulcan” changeup introduced last season.
The addition of Imai improves an Astros rotation that was ravaged by injuries in 2025, a season that ended Houston’s playoff streak dating back to 2016. Three pitchers underwent Tommy John surgery, several others missed significant time, and the club is expected to lose left-hander Framber Valdez in free agency. Along with the recent signing of Ryan Weiss, Imai is part of an effort by Houston to rebuild its pitching depth and stabilize the rotation heading into the new season.
