The Cubs added bullpen help by acquiring left-hander Mike Montgomery from the Seattle Mariners for first baseman and designated hitter Dan Vogelbach.
Chicago also obtained right-handed prospect Jordan Pries in Wednesday's deal. Right-hander Paul Blackburn also goes to Seattle.
The 27-year-old Montgomery has a 2.34 ERA in two starts and 30 relief appearances with the Mariners this season. The former first round pick of Kansas City was traded to Tampa Bay in the 2012 James Shields deal, when the Cubs' Joe Maddon was managing Tampa Bay.
Maddon described Montgomery as "big left-hander with a very good arm."
Vogelbach, 23, was hitting .318 with 16 homers and 64 RBIs in 89 games for Triple-A Iowa. The Cubs selected Voelbach in the second round of the 2011 amateur draft.
Pries, 26, had a 4.93 ERA in Double-A Jackson and Triple-A Tacoma this season. The 22-year-old Blackburn had a 3.17 ERA in 18 starts with Double-A Tennessee.
>>White Sox Trade Carroll To Texas
The Texas Rangers have acquired minor league right-hander Scott Carroll from the Chicago White Sox for cash.
Texas completed the deal Wednesday, and will assign the 31-year-old Carroll to Double-A Frisco. The move comes a week after the White Sox assigned him outright to Triple-A Charlotte.
Carroll appeared in 47 major league games the past three seasons for the White Sox. He made three relief appearances for Chicago from May 6-12 before being sent back to Charlotte, where he was 2-8 with a 5.55 in 16 games (12 starts) this season.
His major league record is 6-11 with a 4.60 ERA. He started 19 of his 47 games.