Eaton was optioned to Triple-A Omaha on Monday, Anne Rogers of MLB.com reports.
Eaton will head back to Omaha after he produced a .188 average with two extra-base hits, an RBI, four runs and a stolen base over 32 at-bats in 15 games after he got called up Aug. 4. His demotion opened a roster spot for Drew Waters, who's expected to make his major-league debut Monday.