The Padres activated Waldron (lower body) from the 15-day injured list Friday.
Waldron is set to make his season debut Friday with a start on the road against the Angels. The knuckleballer got a late start to the season after having hemorrhoid surgery in late February, but he looked sharp in a rehab assignment at Triple-A El Paso, tossing 12 scoreless innings with a 12:1 K:BB. Waldron will have the opportunity to make additional starts for the Padres if he pitches well.