Right-hander Chris Bassitt, the A's projected No. 4 starter, went five innings and endured a rough start.
Bassitt issued bases-loaded walks in the first inning to Eric Hosmer and Alex Gordon. Bassitt gave up seven hits and five runs overall, while throwing 100 pitches, 57 for strikes.
Red-hot Royals outfielder Reymond Fuentes delivered a two-run single in the first. Fuentes appears a lock to make the 25-man roster, and may even be in line to start the home opener on April 3.
Left-hander Danny Duffy also threw two scoreless innings for the Royals.