Rosales is hitting .211 with the River Cats, including .240 (6-for-25) in six games since being designated for assignment by the A's on July 8.
Green, called up that same day in place of Rosales to make his Major League debut, is 0-for-15 with six strikeouts through his first five games. The A's witnessed a similar slow starter in Chris Carter, who, before being traded to Houston, began his career in Oakland hitless through his first 33 at-bats, with 13 strikeouts.
"You create your own opportunities at the big league level, and you have to perform, but we still feel [Green] has the ability to perform," manager Bob Melvin said Tuesday afternoon. "The offensive ability is definitely there. He squared some balls up yesterday, had some better swings. After the first ball he hit hard, he just looked more confident going up there the second time. That's the way it is with younger players."
Offensive struggles aside, Green has also already committed three errors.
"We knew coming in that he's more of an offensive player than a defensive player, and I think that's just more from the fact he's moved around quite a bit, hasn't been in one position, certainly at second base, for a long period of time," Melvin said. "He'll grow into that and be more comfortable."
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.