The Houston Astros are bolstering their pitching rotation with the signing of Japanese right-hander Tatsuya imai, pending a physical. The three-year contract, which includes opt-out clauses after each season, represents a significant investment in international talent for the club, reportedly worth up to $63 million. Imai, a three-time All-Star in Japan, arrives in Houston as one of the most sought-after pitching prospects from nippon Professional baseball, continuing a trend of MLB teams looking to Japan for top-tier arms.
The Houston Astros have reached an agreement with Japanese right-handed pitcher Tatsuya Imai, bolstering their rotation with a highly-regarded international talent. The deal, which is pending confirmation from the club, is a three-year contract with opt-out clauses after each season.
The average annual value of the contract will be the third-highest for any Japanese pitcher, trailing only Yoshinobu Yamamoto’s deal with the Los Angeles Dodgers and Masahiro Tanaka’s former contract with the New York Yankees. This signing underscores the growing trend of MLB teams investing in top pitching prospects from Japan.
The agreement could be worth up to $63 million, according to reports. Imai is guaranteed $54 million, but incentives could push the total value higher. He will earn $18 million per year, with the potential to add $3 million in incentives by reaching 100 innings pitched in 2026. Should he hit that mark, his base salary for both 2027 and 2028 would increase to $21 million.
Imai became eligible for bids from MLB teams after being posted by the Saitama Seibu Lions on November 19, initiating a 45-day negotiation window.
The 27-year-old has been a three-time All-Star in Japan, earning the honor in 2024 and 2025. His arrival in Houston adds depth and experience to a pitching staff looking to contend in a competitive American League.
Imai has established himself as a premier pitcher in Japan over the last three seasons, consistently posting an ERA below 3.00 and averaging more than a strikeout per inning. His 2025 campaign was particularly dominant, going 10-5 with a career-best 1.92 ERA and 178 strikeouts in 163.2 innings pitched. He also participated in a combined no-hitter for the Lions.
Prior to his stellar 2025 season, Imai excelled in 2024, going 10-8 with a 2.34 ERA and setting career highs with 187 strikeouts and 173.2 innings pitched.
Across eight seasons with the Lions, Imai compiled a 58-45 record, a 3.15 ERA, and 907 strikeouts in 963.2 innings. Since 2023, he’s been even more impressive, boasting a 2.18 ERA and averaging 9.5 strikeouts per nine innings.
“Every season, I’ve played with the goal of winning the league championship and the Japan Series, and that ambition won’t change with a new team,” Imai said earlier in the offseason. “I will continue to compete with a strong desire to win and will do everything I can to contribute to my team’s success.”
Imai’s two primary pitches are a four-seam fastball and a slider. His fastball averaged 94.9 mph in 2025, slightly above the MLB average for a right-handed starter (94.6 mph), and can reach the high 90s. His slider averaged 86.2 mph and generated a 46% swing-and-miss rate.
He also features a solid changeup, primarily used against left-handed hitters, averaging 85.5 mph with a 41% swing-and-miss rate in 2025. Imai mixes in a splitter and a 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 posted this offseason, including stars Munetaka Murakami and Kazuma Okamoto. He was widely considered the top pitching prospect coming from Japan for the 2026 MLB season.
At the MLB General Managers Meetings in November, Imai’s agent, Scott Boras, drew comparisons between Imai and Los Angeles Dodgers ace Yoshinobu Yamamoto, highlighting the success of talented Japanese pitchers in the majors. Yamamoto was named World Series MVP in 2025 and a Cy Young Award finalist.
“Without a doubt, he’s done everything Yamamoto has done in Japan,” Boras said of Imai.
