PHILADELPHIA -- Knuckleballer Matt Waldron was recalled from Triple-A El Paso on Sunday by the San Diego Padres, who placed left-hander Adrian Morejon on the 15-day injured list because of right knee inflammation.

Left-hander Ryan Weathers was returned to El Paso after serving as the 27th man in Saturday's doubleheader and taking the loss in a 9-4 defeat in the second game against Philadelphia.

Waldron, a 26-year-old right-hander, is 1-6 with a 7.02 ERA in 12 starts and two relief appearances for El Paso. He has one career start with the Padres, taking the loss as he allowed two runs and four hits over 4⅔ innings in a 2-0 defeat to Washington on June 24.

Weathers is 1-6 with a 6.25 ERA.

Morejon has a 7.00 ERA in one start and seven relief appearances.