Harang is out with lower back spasms. He was scratched from his start Monday night in New York and, after a chiropractor worked on him, the Reds decided to put him on the DL on Tuesday, retroactive to July 1.
Harang is 6-7 with a 5.02 ERA in 17 starts.
Maloney, who went 2-4 with Cincinnati last year, was recalled from Triple-A Louisville. He was 6-5 with a 3.50 ERA this season in the minors. He was set to start Tuesday night at Citi Field.