On Friday, the Cubs traded infielder Brent Lillibridge to the Yankees for a player to be named later or cash considerations, and on Saturday, left-handed reliever Hisanori Takahashi was dealt to the Rockies for a player to be named later or cash considerations. Both began the season with the Cubs.
Stewart was suspended 10 games for violating the loyalty clause in his contract after he made disparaging comments about the Cubs and manager Dale Sveum on Twitter. He last played June 11 at Oklahoma City and was batting .168 (19-for-113) with six doubles, five home runs and 20 RBIs in 40 games before he was suspended.
Jackson was batting .223 with seven doubles, three homers and 23 RBIs in 61 games. He had an earlier stint on the DL with turf toe.
Ha joins Iowa after batting .284 with one homer, 14 RBIs and eight stolen bases in 28 games with the Smokies.
The Cubs also announced that catcher Steve Clevenger, whose Minor League rehab assignment was to end Saturday, was experiencing some tightness in his oblique area. Clevenger will rest and then be re-evaluated by the Cubs' medical staff.
In 15 games with the Cubs, Clevenger hit .327 with five doubles, three home runs, and 11 RBIs.
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.