Rosales, who was slowed by injuries this spring, was vying with Eric Sogard to become Oakland's top utility infielder. A's manager Bob Melvin said Monday's move was a result of Sogard's solid spring and Rosales needing more time at the plate.
"We know he's a better player offensively than he showed last year and certainly this spring," Melvin said of Rosales. "There's probably a lot of reasons for it. This year he had a shoulder injury that set him back some, and couple that with the fact that we had a shorter schedule and he really never was able to get going."
Rosales batted .167 in 18 Spring Training at-bats this year, driving in two runs while walking three times and striking out four times. Sogard, meanwhile, started the spring off hot and finished with a .341 average, two home runs and seven RBIs in 44 at-bats.
With Rosales gone to Triple-A, Sogard said he felt the A's front office gave him a vote of confidence to stay at the big league level in 2012, after he played four games with Oakland in 2010 and 27 in 2011. Sogard said he feels comfortable at second base, third base and shortstop, crediting A's assistant coach Mike Gallego for helping improve his defense.
"It's been nice kind of getting my feet wet the past year or two," Sogard said. "I continue to feel more comfortable up here at this level. Especially this spring, I proved to myself that I could succeed at this level. I think big things are coming, I'm excited."