Astros Prized Free Agent Tatsuya Imai Struggling to Adjust to MLB Lifestyle

Coming from Japan, Tatsuya Imai says he has not adjusted to the 'American lifestyle.'

Apr 10, 2026; Seattle, Washington, USA; Houston Astros starting pitcher Tatsuya Imai (45) throws against the Seattle Mariners during the first inning at T-Mobile Park. | Joe Nicholson-Imagn Images

The Houston Astros, who are struggling in a big way to begin the season, had a pretty quiet offseason. They lost their former ace in Framber Valdez to free agency and traded for Mike Burrows, but their biggest move came via free agency.

Houston was ultimately the victor in the Tatsuya Imai sweepstakes, signing him to a three year deal. Imai was arguably the top free agent coming from the NPB in Japan, a league that has produced a number of stars in recent seasons.

The bidding war wasn't as heated as many thought it would be heading into the offseason and the Astros came as a surprise destination. Imai was seen as a pitcher who could slide into the middle of a rotation and that was something Houston desperately needed. On Tuesday, the right-hander admitted the transition has been difficult.

The Transition is Effecting Imai on and Off the Field

Houston Astros pitcher Tatsuya Imai. | Joe Nicholson-Imagn Images

Imai, 27, was coming off of an excellent season in the NPB. In 24 starts he had a 1.92 ERA, an 0.892 WHIP and 9.8 K/9. Since coming to the states and the beginning of the MLB season, the right-hander has struggled.

In three starts, he's allowed seven earned runs in 8.2 innings, while striking out 13, but walking 11 batters. He's struggled with his command, but the stuff seems to be playing well enough to had a 35.1 percent whiff rate, according to Baseball Savant.

On Monday, however, he hit the injured list with arm fatigue, according to Chandler Rome of The Athletic (subscription required). Speaking to the media on Tuesday, Imai revealed that the imaging on his arm came back clean and the team will "increase his arm strength" before he starts throwing again.

However, Imai revelaed that he believes he knows the reasons for his struggles and even the arm fatigue.

Imai, through his interpreter, told reporters he is "just not able to adjust to the American lifestyle, other than baseball. Baseball and outside of baseball. Thats probably the reason [for his arm fatigue]."

Many of the players coming from Japan haven't adjusted right away. Los Angeles Dodgers pitcher Roki Sasaki is a good example. One of the most highly touted pitchers in Japan's history, Sasaki has had a 4.98 ERA through his first 13 career outings.

It's a different game in the NPB. They pitch every sixth day rather than five, the ball is different and they even have a regular season that's 19 games shorter, which is more equivalent to a Triple-A season. That lends the travel in MLB to be more difficult, which is the thing Imai pointed to.

"For example, the travel is different from Japan. The timing when the players eat. In Japan, when they get back to the hotel, they eat their dinner. Here, the players eat at the stadium," he said.

His interpreter further stated that Imai thought it would be the same as in Japan, according to Rome.

Although manager Joe Espada is optimistic, Imai still won't resume throwing until his arm strength is back, but there is not set timetable.

It's not an easy thing to up and move your entire life like Imai did this offseason. The two cultures are different, the baseball is different. The adjustment won't be easy, but the right-hander is focused on being better.