After signing with the Pirates, Martin made his professional debut with the Rookie-levelGulf Coast League Pirates, slashing .307/.457/.630 with 11 home runs (breaking the GCL Pirates record)[6] and 22 RBI over 39 games, earning the title of Gulf Coast League Most Valuable Player.[7] Martin began the 2018 season with the West Virginia Power of the Single–ASouth Atlantic League, but was reassigned to the Bristol Pirates of the Rookie-level Appalachian League halfway through the year.[8] Over 104 games between the two teams, he batted .220 with 14 home runs and 58 RBI. In 2019, he began the year with the Greensboro Grasshoppers of the Single–A South Atlantic League (with whom he was named an All-Star) before being promoted to the Bradenton Marauders of the High–AFlorida State League in July, with whom he finished the season.[9][10][11] Over 131 games, Martin slashed .254/.351/.558 with 35 home runs and 129 RBI.[12] His 35 home runs were fourth in all of the minor leagues and his 129 RBI were first.[13] Following the season's end, he was named Pittsburgh's Minor League Player of the Year.[14][15]
Martin did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.[16] Martin was assigned to the Altoona Curve of the Double-A Northeast for the majority of the 2021 season, slashing .242/.318/.481 with 22 home runs, 75 RBI, and 29 doubles over 112 games.[17] Following the end of Altoona's season in mid-September, he was promoted to the Indianapolis Indians of the Triple-A East, appearing in eight games in which he hit three home runs to end the year.[18] Martin led all Pittsburgh minor leaguers in home runs (25) and runs batted in (81), while also striking out 171 times over 439 at-bats.[19] He returned to the Indians for the 2022 season.[20] Over 134 games, he slashed .210/.287/.410 with 19 home runs, 74 RBI, and 29 doubles with 194 strikeouts over 481 at-bats.[21]
For the 2023 season, Martin played with Altoona and Indianapolis, batting .215 with 18 home runs and 54 RBI over 97 games.[22] He elected free agency following the season on November 6, 2023.[23]