Kieboom was promoted to Double-A Harrisburg on Thursday, Jorge Castillo of The Washington Post reports.
Kieboom continued to exceed expectations at the High-A level, slashing .298/.386/.494 with 11 home runs, 46 RBI and six stolen bases for Potomac in 61 games this season. The infielder will likely spend the remainder of the 2018 campaign learning the ropes at Harrisburg. Though he's a fine defender at shortstop, Kieboom's eventual home in the majors may wind up being second or third base.