The Nationals optioned Adon to Triple-A Rochester on Tuesday, Jessica Camerato of MLB.com reports.
Adon posted a dreadful 7.10 ERA over 14 starts for the Nationals last season and wasn't viewed as a serious candidate for the Opening Day rotation. The right-hander has displayed plenty of bat-missing ability on the farm but still needs to fine-tune some things before getting another look in the majors.