Martin, 22, has a 2.25 ERA and 24:9 K:BB through 20 innings for High-A Down East.
Martin had a minor elbow ailment in 2016, and opposing batters hit .300 against him during his 69.1 innings last season. Still, he fanned over a batter per inning, a trend that has spilled into 2017. If Martin can stay healthy and develop a steady third pitch, he could become a prospect to watch for the Rangers.