The Athletics selected Wade's contract from Triple-A Las Vegas on Saturday.
Wade is up with the big club to replace infielder Kevin Smith, who landed on the injured list with a strained back. Wade had appeared in 10 MLB games this season, stealing four bases despite striking out in eight of his 16 plate appearances. He has a career .211/.290/.293 slash line across parts of seven seasons in the majors, so he's unlikely to carve out a regular role even on a sub-.500 team like Oakland.