Japanese right-hander Tatsuya Imai has agreed to a three-year deal with the Astros that includes opt-outs after each season, a source told MLB.com’s Mark Feinsand. The club hasn’t confirmed the move.
The AAV of the deal will be the second-largest for any Japanese pitcher behind only Yoshinobu Yamamoto, whose AAV is just over $27 million, a source told Feinsand.
According to Chandler Rome of The Athletic, the pact maxes out at $63 million.
Imai was posted by his Nippon Professional Baseball club, the Saitama Seibu Lions, on Nov. 19, opening MLB teams’ 45-day window to negotiate a contract with him.
The 27-year-old right-hander was a three-time All-Star in NPB, including in both 2024 and 2025.
Imai has emerged as an ace-level pitcher in Japan over the past several years — he’s posted an ERA under three and struck out more than a batter per inning in each of the past three seasons. But the 2025 season was arguably the best of his career. Imai went 10-5 with a career-best 1.92 ERA and 178 strikeouts in 163 2/3 innings and pitched in a combined no-hitter for the Lions.
If it wasn’t 2025, it was 2024, when Imai went 10-8 with a 2.34 ERA and set career highs with 187 strikeouts and 173 1/3 innings pitched.
Overall, in his eight seasons with the Lions, Imai had a 58-45 record, 3.15 ERA and 907 strikeouts in 963 2/3 innings pitched. Since 2023, though, his ERA is just 2.18 and he’s averaged 9.5 strikeouts per nine innings.
“Every season, I have played with the goal of winning the league championship and the Japan Series, and that ambition will not change with a new team,” Imai said earlier in the offseason. “I will continue to compete with a strong desire to win and do my best to contribute to my team’s success.”
Imai’s two main pitches are his four-seam fastball and slider. His four-seamer averaged 94.9 mph in 2025 — slightly above the average for an MLB right-handed starter (94.6 mph) — and can reach the upper 90s. His slider averaged 86.2 mph and generated a 46% swing-and-miss rate.
Imai also throws a good changeup, mainly against lefties, which averaged 85.5 mph in 2025 with a 41% swing-and-miss rate. He mixes in a splitter and curveball as well, and added a new “Vulcan” changeup with a wider grip during the 2025 season.
Imai was one of several high-profile Japanese players to be posted this offseason, including superstar sluggers Munetaka Murakami and Kazuma Okamoto. Imai was regarded as the top pitcher coming from NPB to MLB for the 2026 season.
At MLB’s general managers meetings in November, Imai’s agent, Scott Boras, compared him to Dodgers ace Yoshinobu Yamamoto while noting how talented NPB pitchers like him have become stars in MLB. Yamamoto was named World Series MVP in 2025 and was a Cy Young Award finalist.
“Certainly, he’s done everything that Yamamoto’s done in NPB,” Boras said of Imai.
