The Astros and the right-hander Tatsuya Imai they agreed to a three-year, $54MM contract, according to Jon Heyman of the New York Post. Heyman added that Imai could earn up to $3MM a year in compensation if he reaches 100 innings. The deal includes an exit after a year, according to Jesse Rogers of ESPN.
Imai was one of the top starters available in free agency and is coming off a career-best 1.92 ERA season with the Saitama Seibu Lions of Japan’s Nippon Professional Baseball. It was reported a few days ago that he was meeting with teams in person before the signing deadline on January 2. The Yankees, Mets, Cubs, Phillies, and Orioles were among the clubs interested in signing him, so the Astros are a surprise destination.
We at MLBTR have ranked Imai No. 7 on our Top 50 Free Agents list and inked him a six-year, $150MM contract. This deal with Houston comes in at half the length of that projection, about a third of the guaranteed money. It appeared that Imai had some offers on the table for long terms but low AAVs (link via Mark Feinsand of MLB.com). Opting out of his deal with Houston allows him to try for a bigger contract in the upcoming offseasons if he can prove himself in the MLB.
Imai is 27 (28 in May) and has a 3.15 ERA in 963 2/3 NPB innings. He started 2018 at age 20 and made 16 appearances (15 starts), but struggled with a 4.97 ERA. Those early struggles have continued since 2019-20. In a breakout season, Imai had a 6.13 ERA in 61 2/3 innings and walked more batters than he struck out, which led to him being temporarily moved to the bullpen. He rebounded in 2021, posting a 3.30 ERA in 158 1/3 innings with an improved strikeout rate, and has held on as the starting pitcher ever since.
That came into effect from 2022-25. After posting a 2.41 ERA in nine starts with the Lions in 2022, Imai followed up with a 2.30 ERA and a 24.4% strikeout rate in 133 innings in 2023. Although he walked 11.4% of batters that year, his strikeout and walk numbers improved each year from 2502. This year, he struck out 27.8% of batters (highest among NPB professional starters) and walked 7.0%. His K-BB rate of 20.7% was third in that league. Imai also excelled at keeping the ball in the yard, allowing just six home runs all season (0.33 HR/9) and fielding ground balls 48.3% of the time. Overall, he enters the majors with a higher ceiling and much improved control compared to his early career.
Materially, Imai profiles as a middle rotation starter in the majors. His fastball sits in the mid-90s and can reach 99 mph, and he throws a slider, splitter, and changeup. His excellent performance from 2022-25 made him an attractive target in free agency, though some scouts were concerned about his secondary and past struggles with control. It seemed like industry opinion was mixed on whether he could succeed as a big league starter, leading to a lower-than-expected confirmation.
At the time of his posting, a $150MM deal seemed like a real possibility. These days, teams value youth and upside and are willing to pay a premium to get it. The last season saw the players like Juan Soto again Vladimir Guerrero Jr. signed for over ten years and at least $500MM of guaranteed capital. Among Japanese players, who are right-handed Yoshinobu Yamamoto and foreign player Jung Hoo Lee they reached the majors after their age 24 season and received $100M+ deals. Imai is several years older than Yamamoto when he signed and has a shorter history as a front-of-the-rotation arm. Although he never matched Yamamoto’s deal, Imai’s record of year-to-year improvement and relative youth was enough for the Astros to pay $18MM per year to add him to their rotation.
While Houston’s interest in Imai is not widely known, it makes sense that they want another starting pitcher. Long time ace Framber Valdez he is currently a free agent. The team has held talks with Valdez’s camp, although he is expected to sign elsewhere on a contract basis. Hunter Brown was good in 2025, totaling 185 1/3 innings with a 2.43 ERA. That number ranked third among professional starters, trailing only Cy Young winners Paul Skenes again Tarik Skubal. He also posted an 85th-percentile strikeout rate and a 77th-percentile groundball rate. Overall, he was worth 4.6 fWAR and finished third in AL Cy Young voting. He will return as the ace of the staff in 2026.
More to come.
