The fight's location has yet to be determined.
During the win over Silva, however, Cormier suffered a broken right hand. The injury forced the bout with Barnett to be placed on hold.
"It (the right hand) is finally healed, I'm ready to fight," Cormier said. "Replacement or no replacement, I was given an opportunity and I took it. Now I am fighting the biggest fight of my career.
"I can't wait."
Barnett-Cormier will be the last heavyweight bout under the Strikeforce banner. Fighters in the division now compete in UFC.
Both UFC and Strikeforce are owned by Zuffa, LLC.
Franklin McNeil covers mixed martial arts and boxing for ESPN.com. Follow him on Twitter at www.twitter.com/Franklin_McNeil.