On October 13, , Kiger became the first player since Bug Holliday in to make his major league debut in a postseason game when he appeared as a defensive replacement for D'Angelo Jiménez at second base for the Athletics in Game 3 of the 2006 American League Championship Series (ALCS). He was added to the Athletics roster in the ALCS after starting second baseman Mark Ellis was injured in the 2006 American League Division Series. Oakland had already suffered injuries to Bobby Crosby and Antonio Perez. Kiger was released by Oakland after the playoffs.