But it's not yet known who Tyson Ross will replace on the 25-man roster, as manager Bob Melvin deems the looming decision a tough one.
"Very, to put it succinctly," he said Monday.
Considering the makeup of the roster, first baseman Kila Ka'aihue and outfielder Collin Cowgill appear to be the leading candidates to go, especially because Melvin plans on sticking with the group that currently makes up his seven-man bullpen.
Ka'aihue is a strong possibility, despite being out of options and batting .500 in four games entering Monday. The A's already have a left-handed first baseman in Daric Barton, whom the organization views as the everyday guy moving forward. That means most of Ka'aihue's at-bats would come off the bench or at designated hitter, where he started Monday following Sunday's three-hit performance, but the A's already have two others who can fill both those roles in Seth Smith and Jonny Gomes.
It's also worth noting that Melvin said the choice will not strictly be based on performance.
"How much playing time a certain guy will get, that goes into it," he said. "The decision still hasn't been made, and that's how tough this next one will be."
Cowgill, meanwhile, has received just one start, with two overall appearances through the first 10 games. Yet he represents a true fourth outfielder, and Melvin has repeatedly said he likes the speedster's all-out style of play.
"It's difficult to keep him current, yet I need to," Melvin said. "He's a hard-working kid, always prepared."