Castro (knee) threw a successful bullpen session Monday and is scheduled to pitch Friday against the Pirates, Eduardo A. Encina of The Baltimore Sun reports.
Everything went off without a hitch in Castro's bullpen, clearing the way for him to make his 2018 Grapefruit League debut later in the week. After spending the previous three seasons as a reliever, the 23-year-old is stretched out and set to compete with the likes of Gabriel Ynoa and Mike Wright for the Orioles' final rotation spot in camp.