Ramirez has been on the disabled list since April 16 because of right shoulder inflammation. He made three rehab appearances -- two for Double-A Tennessee and a one-inning outing for Triple-A Iowa. In the three games, he gave up one hit over 2 2/3 scoreless innings while striking out four.
Last season, Ramirez, 26, appeared in 50 games for the Cubs and posted a 1.44 ERA. He was expected to be a key piece of the bullpen this season but was sidelined with the shoulder injury after five outings.
No corresponding roster move was announced after Saturday night's 8-1 loss to St. Louis.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings. You can follow her on Twitter @CarrieMuskat and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.