The Padres recalled Waldron from Triple-A El Paso on Monday.
Waldron will start Monday's game in Philadelphia and could be needed for multiple turns in the rotation as the Padres navigate through injuries to their other starting pitchers. The knuckleballer has missed time himself in 2025 with an oblique strain, and in five starts with El Paso, he turned in a 5.24 ERA, 1.52 WHIP and 22:7 K:BB in 22.1 innings.