The Astros acquired Martin from the Royals on Wednesday in exchange for Nate Pearson.
Martin has logged a 2.01 ERA and 36:13 K:BB over 40.1 innings between Single-A Columbia and High-A Quad Cities this season. The 22-year-old reliever was a 10th-round pick of the Royals in the 2025 First-Year Player Draft.