Peguero (hamstring) threw 30 pitches during a bullpen session Monday, Evan Webeck of the California Post reports.
Peguero landed on the 60-day injured list June 1 due to a left hamstring strain, but it appears his rehab is coming along at a nice pace. He was immediately placed on the 60-day IL after suffering the injury, so he won't be eligible to be reinstated until the end of July. Peguero will presumably be asked to complete at least another bullpen or two before facing live hitters.