Martin was placed on the 7-day disabled list at High-A Down East on Saturday with mild back spasms, MLB.com's T.R. Sullivan reports.
The "mild" descriptor suggests that the Rangers aren't prepping for a long-term absence for Martin, who has become one of the team's more promising pitching prospects in the lower minors. The 22-year-old has compiled a 3.12 ERA and 34 strikeouts over 26 innings for Down East this season.