Adon was optioned to Triple-A Rochester on Monday, Mark Zuckerman of MASNSports.com reports.
After being called up July 7, Adon will return to Triple-A, having allowed three runs on three hits, including two homers, over two appearances with the Nationals while a member of the major-league bullpen. Patrick Corbin was activated from the paternity list Monday and will replace Adon on Washington's roster.