Astros’ Tatsuya Imai Sidelined with "Tired Arm," Returns to Houston for Evaluation

Tatsuya Imai is heading back to Houston for medical evaluation after showing signs of a "tired arm" following a disastrous start against the Mariners. The right-hander, who allowed three runs in just one-third of an inning on Thursday, is returning to the Astros’ medical staff for a closer look. The team is preparing for a busy stretch, and Imai’s potential absence adds another layer of concern to an already depleted rotation.

Imai’s struggles this season are evident in his 7.27 ERA across 8 2/3 innings. His lone quality start came on April 4 against the Athletics, when he tossed 5 2/3 shutout innings at Sutter Health Park. That performance was sandwiched between two rough outings, including a 2 2/3-inning effort against the Angels on March 29 and last night’s brief appearance in Seattle. Imai retired just one of the seven batters he faced, issuing four walks, hitting a batter, and allowing one hit.

Postgame, Imai told reporters (via interpreter) that the cooler weather and hard mound at T-Mobile Park were factors in his performance. He also mentioned adjusting to Major League mounds and the baseball itself. These are common challenges for pitchers transitioning from Nippon Professional Baseball, where starters typically pitch once per week. Imai has had five full rest days between starts, which is more than the standard five-day rotation in MLB.

Imai signed a three-year, $54 million contract with the Astros last offseason, with opt-out clauses after each of the first two seasons. The deal was below some projections, as teams questioned whether he could replicate his NPB success in the majors. The situation could now become a turning point for both Imai and the Astros.

The Astros’ rotation is already in disarray. Hunter Brown and Cristian Javier were recently placed on the 15-day injured list with Grade 2 shoulder strains. Both are expected to be sidelined until at least May. With only three starters currently available, Imai, Mike Burrows, and Lance McCullers Jr., the Astros may turn to Cody Bolton, J.P. France, Ryan Weiss, AJ Blubaugh, or Jason Alexander for spot starts or piggyback roles.

The Astros have 13 games in 13 days ahead of them, with no off-day until April 23. That gives manager Joe Espada little time to adjust the rotation. Imai’s status will be reevaluated in Houston, and a decision on his availability for Friday’s game will likely come soon.