The Padres placed Waldron on the 15-day injured list Friday due to a right brachialis muscle injury.
Waldron was initially DFA'd by the Padres earlier in the day, but he'll instead go on the injured list with a forearm injury. It's his second stint on the 15-day IL this season, with a lower-body injury causing him to miss the first three weeks of the 2026 campaign. Right-hander Alek Jacob was recalled from Triple-A El Paso in a corresponding move.