The Royals optioned Zerpa to Double-A Northwest Arkansas on Sunday, Anne Rogers of MLB.com reports.
Zerpa was summoned from the minors to make a spot start for the Royals late in the 2021 season, and though he acquitted himself well by striking out four while allowing two unearned runs in five innings in a Sept. 30 loss to Cleveland, he never looked like a serious threat to win a spot on Kansas City's Opening Day roster. Instead, Zerpa will return to the Double-A level in search of better results after he submitted a 5.96 ERA and 1.55 WHIP in 45.1 innings for Northwest Arkansas in 2021.