Option declined following 2017 season.
Castillo is a young defender with good technique who will provide the Rapids depth along the backline.
COLLEGE: Was named the 2015 Atlantic 10 Defensive Player of the Year and was a four-year starter for the Rams, starting all 80 games he saw action in, a school record. The San Jose, Costa Rica native scored 17 collegiate goals and notched two assists which also earned him NSCAA Second Team All-Midwest Region, Atlantic 10 Championship Player and Atlantic 10 First Team All-Conference. Castillo has also represented the Costa Rica national team at the U-18 and U-20 levels.