Acosta has spent the past two seasons at Triple-A Durham. Last season, he played in 16 games for the Bulls, hitting .083 with three RBIs.
O'Conner is ranked by MLB.com as the Rays' No. 8 prospect. He spent 2015 at Double-A Montgomery. Tampa Bay president of baseball operations Matt Silverman told reporters on Thursday that O'Conner has been slowed by the injury.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.