Barreto went 2-for-5 with a single and a two-run homer in his major-league debut Saturday.
Despite running on fumes -- he admitted that he didn't sleep after learning of his callup -- Barreto muscled a home run off James Shields in his first career start. The 21-year-old packs a real punch despite standing just 5-foot-10, 190 pounds, as evidenced by his eight homers with Triple-A Nashville prior to his promotion. Barreto figures to see starts at second base and short while several of the A's veteran infielders are on the mend.