Waldron (forearm) is scheduled to throw two innings of a bullpen session Tuesday and is on track to start a rehab assignment with Triple-A El Paso this Sunday, Jeff Sanders of The San Diego Union-Tribune reports.
Waldron landed on the 15-day injured list in mid-May due to a right brachialis muscle injury, his second stint on the IL this season. He's progressed enough in his recovery to close in on a rehab assignment, and he could back with the big club after a couple of outings in the minors. When he returns to the majors, Waldron will likely operate out of the Padres' bullpen after Lucas Giolito was added to the rotation.