“I felt good today,” Castillo told reporters on Tuesday. “My arm feels fine. My body feels fine. Everything feels health. It’s a small step toward the next step.”
Castillo would become the 37th Reds player to pitch for the Dragons on a rehab assignment. It will be his first appearance with the Dragons. He spent most of his minor league career in the Miami Marlins organization before the Reds acquired him in a trade in 2017. He pitched for Double-A Pensacola in the Reds system before making his big-league debut on June 23, 2017, with the Reds.