Maine, who went 1-1 with a 4.79 ERA in three short stints with the Cubs this season, was assigned to Columbus and right-hander Jeanmar Gomez was recalled from the Triple-A team. The 27-year-old Maine also went 4-2 with five saves and a 2.88 ERA in 28 games from Triple-A Iowa.
The 32-year-old Duncan hit .203 with 11 homers and 31 RBIs in 81 games, mostly in left field, for Cleveland.
Gomez opened the season in the Indians' rotation and went 4-7 with a 5.18 ERA before being optioned to Columbus. With the Clippers, the 24-year-old had a 6-5 record and 4.41 ERA in 11 starts.