Barreto will start at second base and bat second Sunday against the Mariners.
The rookie will enter the lineup in place of Jed Lowrie, who receives a breather after starting 15 of the Athletics' last 16 contests. A likely long-term heir to a full-time role in the middle infield, Barreto may have to settle for sporadic at-bats in the final month of the season with both Lowrie and Marcus Semien seemingly in line to retain starting roles for the big club heading into 2018, assuming the Athletics exercise Lowrie's affordable $6 million club option this offseason.