CHICAGO -- Cubs slugger Kyle Schwarber's stay at Triple-A Iowa is over with manager Joe Maddon convinced a hitting slump for the left-handed power hitter is also coming to an end.Schwarber rejoined the team and was installed in the starting lineup for the series finale with the Milwaukee Brewers, batting fifth and playing left field."Now that I was able to go down there and hash everything down ... stop thinking about it, it was all a really positive experience for me," Schwarber said Thursday before batting practice. Schwarber spent 11 games on the roster of the Chicago Cubs' Triple-A affiliate in Des Moines, Iowa, belting four home runs and batting .343 (12 for 35). Schwarber had a .171 average and 12 home runs in 64 games with the Cubs this season. He agreed to the demotion and kept a positive mindset in the minors. Schwarber smacked an opposite field home run in a two-homer effort on Saturday."You've got to go back to what made you successful in the first place," Schwarber said of his approach, which includes focusing on taking the ball the other way. A pronounced shift to beat the pull tendency from Schwarber this season has been effective. Maddon said he wanted Schwarber to "get himself right" and use the entire field.Right-hander John Lackey was placed on the disabled list to make room for Schwarber. Lackey is dealing with plantar fasciitis, but might not miss a start due to the timing of the All-Star Break next week. Right-hander Kyle Hendricks is also close to returning to the rotation.Maddon said Wednesday that Schwarber might get at-bats in the leadoff role but also made an argument for using Jon Jay in the No. 1 spot in the order against right-handed starters.