Kieboom is starting at third base and batting fifth Thursday versus the Yankees.
Jake Alu is poised to play more in left field with the Nationals losing Stone Garrett to a fractured left fibula Wednesday, which likely shifts Ildemaro Vargas into the bulk of starts at second base and opens up a lot of reps for Kieboom at third. The 25-year-old former top prospect hit a solo home run Tuesday off Carlos Rodon in his first major-league at-bat since 2021. He had posted a .789 OPS with five homers and 23 RBI in 34 games for Triple-A Rochester prior to his promotion.