Castro was moved off the 40-man roster to clear a spot for right-hander Hayden Wesneski, who was promoted from Triple-A Iowa to presumably take over the rotation spot of the injured Justin Steele (back). After being claimed off waivers from the Giants in August, Castro surrendered nine earned runs on 11 hits and five walks across 10.2 innings over his eight appearances with the Cubs before being optioned to Iowa two weeks ago.
