He saw big league action for four different teams (the Diamondbacks, Mets, Mariners, and Orioles) while compiling a 3.94 ERA over 32 innings. Beginning the season on a minor league deal with Arizona, Castillo was designated for assignment in May and then traded to the Mets, and he subsequently bounced around on a series of waiver claims. Castillo actually had three separate stints with the Mets, with the latest coming in early November when he was claimed off Baltimore's waiver wire.