The team also sent down struggling reliever Wandy Peralta, who has a 19.10 ERA in his last 10 appearances.
Kyle Crockett was called up from Louisville to take Peralta’s place.
>>RELATED: What’s gone wrong with Wandy Peralta?
A left-hander from Virginia, Crockett was a fourth-round pick of the Cleveland Indians in 2013.
He appeared in 107 games for the Tribe (all as a reliever) from 2014-17 with a 3.44 ERA.
This year for Louisville he has a 4.00 ERA in 23 relief appearances. He has struck out 23 and walked five.
Ervin began the season with the Reds, hitting .211 with three RBIs and five runs scored in 16 games.
The 2013 first-round pick is hitting .221 with no home runs, 10 RBIs and seven stolen bases in 27 games for the Bats.
In addition to those moves, the Reds released Tony Cruz, who was with the Bats.