Santillan (0-1) allowed four runs (two earned) on two hits and two walks to blow the save and take the loss Thursday against the Diamondbacks.
Santillan entered the game in the ninth inning in a save situation, but he unraveled by retiring just two of the six batters he faced. While he has served as Cincinnati's closer of late, Santillan has allowed at least one earned run in each of his last three appearances while giving up eight hits and three walks across just 2.1 frames. Art Warren or Alexis Diaz could start to earn more work in the ninth inning if Santillan's struggles continue.