Blackburn will start Game 2 of Saturday's doubleheader against the Mariners, Matt Kawahara of the San Francisco Chronicle reports.
Blackburn will return to the active roster Saturday after spending nearly a month at the Athletics' alternate training site. The right-hander failed to make an appearance during his first stint in the majors this year, but he'll make his season debut during Saturday's twin bill as Oakland prepares for the postseason.