Hernandez (calf) is scheduled to throw a bullpen session Saturday, Jason Mackey of the Pittsburgh Post-Gazette reports.
Hernandez appears on track to return from the 15-day injured list when first eligible next week. Selected away from the Dodgers in the Rule 5 Draft back in December, the 25-year-old left-hander had registered a sharp 2.63 ERA and 28:6 K:BB through 27.1 innings this season with Pittsburgh prior to suffering a minor right calf strain.