Leiter (ankle) reported biceps soreness after the first inning of his latest rehab outing at Triple-A Round Rock on Wednesday, Zach Sweet of MLB.com reports.
The Rangers will shut Leiter down from throwing for a few days before reevaluating him. Manager Skip Schumaker said Friday that Leiter's setback will make it harder for him to return this season as a starter, but he may still be able to contribute out of the bullpen if he's able to get fully healthy.