The Reds recalled Dunn from Triple-A Louisville on Sunday.
The 27-year-old will get his first look in the big leagues this season with Rece Hinds being demoted to Louisville. Dunn has a .151/.298/.256 slash line across 49 career MLB games and isn't likely to see significant playing time while up with the Reds, though he could net some starts versus left-handed pitching.