MILWAUKEE -- Jake Arrieta, who made his fifth Minor League rehab start on Saturday, will join the Cubs in Cincinnati on Monday. When the right-hander returns to the rotation is still to be determined.
Arrieta was slowed this spring by tightness in his right shoulder. On Saturday, he threw 44 pitches over two innings for Double-A Tennessee, which was a short outing because it's the equivalent of the last Spring Training start for pitchers.
"Jake did a nice job yesterday," Cubs manager Rick Renteria said. "He worked through it healthy, and we'll see where he's at once we put our eyes on him."
Carlos Villanueva is 1-3 with a 10.19 ERA in four starts, and he is scheduled to pitch Wednesday in the series finale against the Reds. It's unlikely Arrieta would be activated and take Villanueva's spot, pitching on four days' rest, but Renteria said no decision would be made until he and pitching coach Chris Bosio get a chance to see the right-hander.
Acquired from the Orioles last July in the Scott Feldman deal, Arreita was 4-2 with a 3.66 ERA in nine starts for the Cubs.
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.