Santillan (1-4) was the losing pitcher Monday, allowing two runs (one earned) while walking one in a 2-1 extra-inning loss to the Brewers.
Santillan, who entered a scoreless tie in the 10th inning, gave up runs for the first time in eight outings. Monday's results aside, he appears to have settled in as the Reds fill-in closer until Emilio Pagan (hamstring) returns, which could happen within a week. Pagan threw a second live batting-practice/simulated-game session Monday and is expected to begin a brief rehab assignment Thursday.