Castillo was traded from the Blue Jays to the Royals on Tuesday along with Samad Taylor in exchange for Whit Merrifield, Mark Feinsand of MLB.com reports.
This trade came in right at the deadline, and it's probably a mildly good development for Castillo's fantasy value. He emerged as a significant prospect this season, logging a 1.92 ERA, 0.98 WHIP and 64 strikeouts in 56.1 innings between Double-A and Triple-A. Castillo also logged a 3.05 ERA, 0.97 WHIP and 20:5 K:BB in 20.2 innings in the majors, working as both a starter and a reliever. It should be easier for him to crack Kansas City's rotation in the coming weeks/months. His ability to turn a big-league lineup over multiple times will be put to the test.