Thames announced his retirement from professional baseball on Wednesday.
Thames was released by Oakland on Tuesday, Melissa Lockard of The Athletic reports.
Thames was reassigned to Triple-A Las Vegas on Monday, Matt Kawahara of the San Francisco Chronicle reports.
Thames hopes to return to the majors and "play in front of my family," according to Matt Kawahara of The San Francisco Chronicle.
Thames signed a minor-league contract with the Athletics on Friday, Susan Slusser of the San Francisco Chronicle reports.
Thames' club portion of his mutual contract option was declined by the Nationals on Wednesday, Jesse Dougherty of The Washington Post reports.
Thames isn't in the lineup for Game 1 of Saturday's doubleheader against the Mets.
Thames is not in Thursday's lineup against the Mets.
Thames isn't in Wednesday's lineup against the Phillies.
Thames will sit Monday against the Phillies.