The Padres optioned Waldron to Triple-A El Paso on Thursday, Dennis Lin of The Athletic reports.
Waldron has given up 22 earned runs across his last 14.1 innings spanning three starts, and now the Padres will try to get him back on track in the minors. It's unclear who will take over Waldron's spot in the rotation, though Randy Vasquez is on the same pitching schedule as Waldron and would be a natural fit to return from Triple-A to fill the opening.