It's not a return of the entire opening-day starting rotation for the Houston Astros. But it is a start. Per Chandler Rome of The Athletic on X (formerly Twitter), the Astros will activate and start Tatsuya Imai on Tuesday against the Seattle Mariners. Before Sunday's game against Cincinnati, Houston’s entire rotation for the series was TBD. Rome also reported that Peter Lambert will take the ball on Monday in the series opener. But getting Imai back could be a significant boost for the Astros, even though his injury led to much conversation about his ability to adjust to Major League Baseball. Tatsuya Imai’s Rough Start Houston Astros starting pitcher Tatsuya Imai. | Joe Nicholson-Imagn Images Imai joined the Astros on a three-year contract after a successful career in his native Japan in the NPB. He signed with Houston just before his posting period expired. The deal has opt-outs after each of the first two seasons. But his time with the Astros has been rough.…