Kieboom went 2-for-5 with a solo home run and a stolen base for High-A Potomac in Sunday's win over Lynchburg.
The Nats' No. 3 fantasy prospect has been on a tear lately, hitting safely in nine of his last 10 games with a .351 (13-for-37) batting average, four homers, two steals, 12 runs and 14 RBI. Kieboom now has a .296/.386/.491 slash line through 56 games at High-A with 10 home runs, six stolen bases and a strong 34:48 BB:K, and the 20-year-old seems headed for a promotion to Double-A before the summer is over.