Cincinnati re-signed Santillan on Thursday to a minor-league contract with an invitation to spring training.
Santillan has been bogged down by various injuries over the last two seasons, but he posted a shiny 2.91 ERA with 56 strikeouts over 43.1 innings as a rookie in 2021. With better luck on the health front, the 26-year-old right-hander could reestablish himself as a useful part of the Reds' bullpen mix in 2024.