Martinez remained in the Oakland organization until the Houston Astros selected him in the 2020 Rule 5 draft, and he made his MLB debut in 2021.

Martinez was born and grew up in Sierra Vista, Arizona, and attended Sunrise Mountain High School, where he played baseball and golf.

[7] On December 10, 2020, the Houston Astros selected Martinez in the minor league phase of the Rule 5 draft[6] and assigned him to the Triple–A Sugar Land Skeeters to start the 2021 season.

[9] Martinez earned his first major league win on September 15, after tossing a scoreless inning versus the Oakland Athletics.

[11] He also made 13 appearances at Sugar Land in 2024, with no decisions, a 1.46 ERA (2 runs in 12+1⁄3 innings), 6 hits, 7 walks, 12 strikeouts and 1.054 WHIP.