Through parts of four Major League seasons with the Mariners and Royals, Peguero has hit .196 with nine homers and 28 RBIs in 69 games.
The Royals' 40-man roster now sits at 39.
Joey Nowak is a reporter for MLB.com. Follow him on Twitter at @joeynowak. This story was not subject to the approval of Major League Baseball or its clubs.