The Nationals optioned Adon to Triple-A Rochester on Saturday.
Adon was returned to the minors one day after he was summoned from Rochester to make a spot start during the Nationals' doubleheader Friday with the Phillies. Though he tied his season high with six strikeouts in the outing, he gave up four runs on seven hits and a walk and was dealt his league-high 11th loss. Adon will now make regular turns in the Triple-A rotation with the Nationals having settled on Paolo Espino and Jackson Tetreault as the back-end options in its rotation until at least one of Stephen Strasburg (ribs) or Anibal Sanchez (neck) returns from the injured list.