Abreu was acquired Thursday from the Tampa Bay Rays for minor-league right-hander John Meloan and cash. He is the 26th pitcher to appear on Cleveland's active roster this season.
In two games with Tampa Bay, Abreu had no record and a 2.45 ERA after being called up from Triple-A Durham, where he went 3-0 with 10 saves in 10 chances and a 1.41 ERA.
The 39-year-old Herges was signed by the Indians to a minor-league contract in January and split the season between Triple-A Columbus and Cleveland. In 21 appearances out of the Indians' bullpen, he went 2-1 with a 3.55 ERA.