Astros rotation experiment hints at deeper concerns even after Tatsuya Imai signing

On Monday, the Houston Astros introduced their newest pitcher, Tatsuya Imai. The Japanese star received a warm welcome from the Houston media at his introductory press conference, and Imai seems ready to get to work, saying, “What’s up, H-Town? I’m ready to chase a world championship. Let’s go, Houston. Thank you so much.”

Imai is expected to join the Astros rotation during the upcoming season, but rather than being joined by four other starting pitchers, it sounds like manager Joe Espada plans deploy a six-man rotation; at least at the outset of the 2026 season.

Espada told Chandler Rome of The Athletic (subscription required), “You’ll see a six-man rotation more often this season." Rome noted that Espada's plan centers around Imai's pitching schedule — in Japan, pitchers typically operate on five-days rest.

Astros are planning to head into 2026 with a six-man starting rotation

But there's more to the impending six-man rotation than just Imai's comfort level. Houston still has several unknowns heading into spring, and the opening of 2026 campaign includes 26 games over the first 28 days.

Even with the addition of Imai, the Astros rotation faces a lot of scrutiny. Outside of Hunter Brown, Houston's group of starters is largely unproven. Injuries have defined Lance McCullers Jr. to this point in his career, and Cristian Javier made just eight appearances last season after missing the first several months while recovering from Tommy John surgery.

The Astros made two high-upside acquisitions this winter. Houston signed Ryan Weiss to a Major League deal after his success overseas, and agreed to terms with Nate Pearson. Both are expected to compete for a spot in the Astros rotation this spring, but neither pitcher can be counted on to be a sure thing.

Brandon Walter will miss the entire 2026 season after suffering a torn UCL at the end of last season. Ronel Blanco will be sidelined to begin the year as well as he rehabs from Tommy John surgery, and Houston will also be without Hayden Wesneski.

In short, the Astros' six-man rotation could be more about necessity rather than practicality. Adding Imai took away some of the urgency the Astros were facing this offseason, but given his lack of Major League experience, there's little certainty heading into the 2026 season.