Woodruff was optioned to Triple-A Colorado Springs on Monday.
After holding his own in a spot start Sunday -- he allowed one unearned run on one hit and two walks across four innings -- Woodruff will head back to the minors to open up a roster spot for Eric Thames (thumb), who was brought back from the disabled list in a corresponding move. The 25-year-old will rejoin the Sky Sox's rotation, where he owns a solid 2.10 ERA across six starts this season.