Pagan was optioned to Triple-A Nashville on Saturday, Susan Slusser of the San Francisco Chronicle reports.
Pagan, who hasn't pitched since Aug. 19, was sent to the minors to free up a roster spot for Sunday's starter Chris Bassitt, who is set to be promoted from the Sounds in a corresponding move. In his last appearance, Pagan surrendered a trio of solo homers across three innings, raising his ERA from 3.40 to 3.71. He should be back with the A's sometime in early September after rosters expand.