Double-A Northwest Arkansas placed Wallace on its 7-day injured list May 22 with a right oblique strain, MLB.com reports.
According to the report, Wallace is facing a six-week recovery timeline, meaning that he likely won't be back in action for Northwest Arkansas until shortly before or after the All-Star break. The 22-year-old third baseman is hitting .282 with three home runs and two stolen bases over 140 plate appearances for the Double-A club this season.