Waldron (forearm) struck out one batter while allowing one run on eight hits and no walks over four innings in a rehab start Wednesday with Triple-A El Paso.
Making the fourth start of his rehab assignment as he works his way back from a right brachialis strain, Waldron got stretched out to 60 pitches and threw 42 strikes. Waldron is slated to make another start for El Paso on Tuesday, which could set the stage for him to return from the 15-day injured list later this weekend or immediately following the All-Star break. San Diego may not have a spot available in its rotation for Waldron, so he could serve as a long reliever once he's activated.