Cormier had originally been expected to fight on a Strikeforce: Challengers card on Aug. 13, but was reassigned.
Last weekend, the two-time U.S. Olympian wrestler earned his third straight win, defeating Lucas Browne at Xtreme MMA 2 in Sydney, Australia. Prior to that victory, the 31-year-old had won his first two fights under the Strikeforce banner.
The 31-year-old is 3-0 in his budding career, with all three victories coming via TKO stoppage.
The Strikeforce: Houston show will emanate from the Toyota Center and air on Showtime. In the main event, "King Mo" Muhammed Lawal will defend his light-heavyweight championship for the first time, taking on Rafael "Feijao" Cavalcante. Meanwhile in a fight for the recently vacated middleweight belt, Tim Kennedy will face Ronaldo "Jacare" Souza.
According to Strikeforce, Cormier's bout will take place on the undercard.
Riley, meanwhile, is 7-3 in his pro career, The 6-foot-5, 240-pounder most famously fought Tim Sylvia in the main event of an Adrenaline show, losing by first-round TKO.