The Red Sox announced that they have claimed right-hander Max Castillo off waivers from the Royals. The righty was designated for assignment before the holidays but lingered in DFA limbo for a while since the normal seven-day window is paused between Christmas and New Year’s. Boston’s 40-man roster is now at 40, though their deal with Lucas Giolito has not yet been made official.
Castillo, 25 in May, has 59 2/3 innings of major league experience to this point in his career. He has a 5.43 earned run average in that time, having stuck out 18.1% of batters faced, walked 9.3% and kept 44.7% of balls in play on the ground.
Acquired from the Blue Jays alongside Samad Taylor in the Whit Merrifield trade, Castillo spent most of 2023 in Triple-A Omaha. He threw 116 innings at that level with a 4.58 ERA, 19.2% strikeout rate, 5.7% walk rate and 38.8% ground ball rate.
Castillo still has an option year left, so he’ll give the Sox some extra rotation depth for now. The Boston rotation currently projects to feature some combination of Giolito, Brayan Bello, Nick Pivetta, Kutter Crawford, Tanner Houck and Garrett Whitlock but Castillo will give them another arm and can be kept in Worcester. Pivetta is an impending free agent and Giolito can opt out of his deal after 2024 as well. That creates some long-term uncertainty though the Sox have been connected to free agents like Blake Snell and Jordan Montgomery. Perhaps the club will convert Castillo to relief at some point to see if that unlocks another gear. Castillo still has less than a year of service time, giving him the club plenty of cheap control if he takes a step forward.