The Athletics selected Bolte's contract from Triple-A Las Vegas on Tuesday.
Bolte was off to a scorching-hot start at Las Vegas, slashing .348/.418/.658 with 12 home runs and 17 stolen bases across 177 plate appearances. The 22-year-old outfielder can handle all three outfield spots and could push the struggling Lawrence Butler (.179/.278/.282) for playing time in center field.