Tatsuya Imai

Tatsuya Imai (今井 達也)

• Bats Right, Throws Right
• Height 5' 11", Weight 154 lbs.
• High School Sakushin Gakuin High School
• Debut March 29, 2026

• Born May 9, 1998 in Kanuma, Tochigi, Japan

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Biographical Information

Tatsuya Imai pitched in Nippon Pro Baseball form 2017 to 2025, after which he was posted in order to join Major League Baseball.

Imai represented Japan in the 2016 U-18 Asia Baseball Championship, and he pitched 5 innings with only one run allowed in the final game to help Japan win Gold. The Seibu Lions selected him in the first round of the 2016 NPB draft, but he spent his rookie season in the NPB Farm Leagues due to a right shoulder injury. Imai joined the rotation in 2018, and he went 5-5 with a 4.81 ERA. He started for the Lions in Game 4 of the final stage of the 2018 PLCS, but he allowed 4 runs in 4 2/3 innings and Shota Takeda got the win over him. The Lions were beaten by the Fukuoka Softbank Hawks in 5 games. Imai also got one vote for the 2018 Pacific League Rookie of the Year Award, finishing sixth behind Kazuki Tanaka's 112 votes, Yoshinobu Yamamoto's 70, Ren Kajiya's 45, Yudai Fujioka's 17 and Kotaro Kiyomiya's 2.

The Tochigi native remained in the rotation in 2019, but he faced control problems, and he ranked 2nd in walks in the PL (3 behind Kodai Senga). Despite the walks, Imai was a productive starter as he was 7-9 with a 4.32 ERA, and ranked 9th in strikeouts (122 behind Senga). He started in Game 2 of the final stage in the 2019 PLCS, but he allowed 6 runs in 2 2/3 innings and the Lions were beaten by the Hawks again. He struggled in 2020 as his ERA rose to 6.13 in 19 starts. Imai finally broke out in 2021. He still walked tons of batters, but he realized that his stuff could cover his bad command, so he recorded a 3.30 ERA in 25 games. He led the league in walks with 99, but also ranked 5th in Ks, 69 behind Yamamoto. Imai also relieved Yamamoto in the third inning of 2021 NPB All-Star Game 1 with a 2-0 lead, and pitched 2 shutout innings. He allowed a Ryosuke Kikuchi single, retired Ryutaro Umeno, gave up a hit to Koji Chikamoto then struck out Hayato Sakamoto and got Teruaki Sato on a fly. In the 4th, he got Seiya Suzuki and Kazuma Okamoto. Dayán Viciedo singled but he recovered to whiff Jefry Marté. Naoyuki Uwasawa took over with a 3-0 lead over the Central League but the bullpen couldn't hold on.

The Sakushin alumni suffered a left ankle injury, so he only started 9 games in 2022. In the first stage of the 2022 PLCS, he started in Game 2 but allowed a grand slam to Yuki Yanagita in the 3rd inning. He allowed another run in the next inning, and Keisuke Honda relieved him. Nao Higashihama and the Hawks eliminated them in this game, and Imai got the loss. After this season, he changed his uniform number to "48", in order to honor veteran Shota Takekuma, who retired after 2022. Imai improved in 2023 as he had a 10-5 record with a 2.30 ERA, but his command problem was still terrible. He ranked 4th in wins (6 behind Yamamoto) and 6th in strikeouts (39 behind Yamamoto), but also led the league in walks and hit-by-pitches. He started the Gold Medal Game of the 2023 Asia Professional Baseball Championship but got a no-decision in Japan's 4-3 win over South Korea.

He closed out the PL's 2024 NPB All-Star Game 2 win over the CL, allowing two runs in two innings, but that was better than the average hurler that day in a 16-10 slugfest. In 2024, he was 10-8 with a 2.34 ERA and 187 K in 173 1/3 IP. He trailed only Liván Moinelo and Natsuki Takeuchi in ERA and was tied for 7th in wins (with Takayuki Katoh, Roki Sasaki, Takeuchi and Sachiya Yamasaki), 4th in IP (173 1/3, between Hiromi Itoh and Takahisa Hayakawa), led in walks (70, 19 more than #2 Carter Stewart) and led in strikeouts (187, 26 more than #2 Itoh). Starting 2025 NPB All-Star Game 2, he yielded one unearned run in 1 2/3 IP; Chihiro Sumida took over in a PL 10-7 win. That summer, he was 10-5 with a 1.92 ERA. He was 4th in ERA (between Tomohisa Ohzeki and Hiroya Miyagi) , tied Sumida for 7th in victories, 2nd in complete games (5, one behind Itoh), tied Shoma Kanemura for the shutout lead (3), was 5th in IP (163 2/3, between Aren Kuri and Atsuki Taneichi), cut his walk total down to 45 (tying Koki Kitayama for 5th), finishing second with 178 K (17 behind Itoh) and leading in WHIP (.89).

Following the 2025 season, the Saitama Seibu Lions announced that they would accede to Imai's request to be posted in order to play in Major League Baseball. This was done on November 18th, giving MLB teams until January 2, 2026 to make an offer for his services. He told the media that contrary to some prominent countrymen in recent years, he did not want to join the juggernaut that were the Los Angeles Dodgers. In an interview with former major leaguer Daisuke Matsuzaka on a Japanese radio station shortly after being posted he stated: "Of course, I’d enjoy playing alongside Ohtani, Yamamoto, and Sasaki, but winning against a team like that and becoming a world champion would be the most valuable thing in my life. If anything, I'd rather take them down." He was true to his word as on January 1, 2026, it was announced that he had agreed on a three-year contract with the Houston Astros worth $54 million. He made his debut with Houston on March 29th, as the starting pitcher against the Los Angeles Angels. It wasn't his greatest outing, as he gave up 4 runs on 3 hits and 4 walks in 2 2/3 innings, but he ended up with a no-decision. He missed a month of action between early April and early May, then in his third start after his return and sixth overall on May 25th, he started a combined no-hitter against the Texas Rangers at Globe Life Field. He pitched the first six innings, giving up 4 walks but no hits and striking out two while expending 97 pitches. Three of the walks came in the 1st inning, but he managed to escape that jam and was dominant afterwards, only leaving because his pitch count was getting high. He was succeeded by Steven Okert for one inning and Alimber Santa, who made his major league debut in the game, for the final two, as Houston won handily, 9-0.

Imai's repertoire features a fastball that peaks at 99 mph, a cutter, changeup, curveball and a slider.

Further Reading

• David Adler: "What to expect from Tatsuya Imai? Here are 5 MLB comparisons", mlb.com, November 30, 2025. [1]
• David Adler: "Wait, aren't sliders supposed to break the other way?", mlb.com, April 7, 2026. [2]
• Michael Clair and Ayako Oikawa: "Imai doesn't want to join Dodgers, he wants to 'take them down'", mlb.com, November 24, 2025. [3]
• Brian McTaggart: "Japanese righty Imai agrees to deal with Astros", mlb.com, January 1, 2026. [4]
• Brian McTaggart: "Imai wows at Astros camp: 'Never seen a pitch like that before in my life'", mlb.com, February 20, 2026. [5]
• Brian McTaggart: "Imai teams up with Okert, Santa on Astros' 18th no-hitter in franchise history: Houston combines to toss 1st no-no in MLB since 2024", mlb.com, May 26, 2026. [6]
• Brian Murphy: "Japanese pitcher Tatsuya Imai to be posted by Seibu Lions", mlb.com, November 10, 2025. [7]
• Brian Murphy: "Star Japanese pitcher Imai posted, has until Jan. 2 to sign", mlb.com, November 18, 2025. [8]

Related Sites

• Tatsuya Imai on mlb.com
• BR Register page