CHICAGO -- Jake Arrieta, acquired from the Orioles in the Scott Feldman deal, will join the Cubs' rotation and start Friday against the Cardinals, while Carlos Villanueva is headed back to the bullpen.
Arrieta, 27, was sent to Triple-A Iowa after he was acquired, but he did make one start for the Cubs on July 30 in the second game of a doubleheader against the Brewers, giving up one run on two hits and three walks over six innings. At Iowa, he was 2-2 with a 3.56 ERA in seven starts, striking out 39 over 30 1/3 innings.
Cubs manager Dale Sveum said they want the right-hander to join the team for the final six weeks of the season so pitching coach Chris Bosio can work with him.
The Cubs could've bumped Chris Rusin, but the lefty has done well (2-1, 3.08 ERA) entering Wednesday's start against Cincinnati.
"Not that Villanueva was doing horrible, but Rusin was doing really, really well, and it was hard to bump a guy who's given up one run or no runs every outing since he's been here," Sveum said. "'Villa' has done it before. Losing [Matt] Guerrier, he can be that guy in the sixth or seventh inning when we're winning and get people out."
Guerrier is sidelined with an elbow injury and will not return this season.
Villanueva, 29, began the season in the rotation, but he was shifted to the bullpen when Matt Garza returned from the disabled list. The right-hander is 1-7 with a 4.50 ERA in 15 starts, and 1-1 with a 3.06 ERA as a reliever. Villanueva's only win as a starter came April 18 against the Rangers.
The Cubs' rotation for the upcoming series against the Cardinals will be Arrieta on Friday, Travis Wood on Saturday and Edwin Jackson on Sunday.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.