Rising middleweight Tim Kennedy and undefeated newcomer Zak Cummings have vebrally agreed to meet at Strikeforce’s next Challenger Series on Sept. 25 at the SpiritBank Center in Tulsa, Okla.

If signed, Cummings will replace Evangelista “Cyborg” Santos, who withdrew from the bout Wednesday due to a knee injury, as first reported by The Fight Network.

It is unclear if the bout will remain the headlining bout for the event, said sources close to the event.

Kennedy, a U.S. Army ranger, submitted Nick Thompson with punches in his debut for the promotion on June 19 in Kent, Wash. He holds a win and loss against Jason “Mayhem” Miller and has won 10 of his last 11 fights.

On of Strikeforce’s recent signings, Cummings earned a split decision over UFC and Affliction veteran Terry Martin at an XCF event on Feb. 14 in Daytona, Fla. Cummings scored his tenth pro victory with a first-round technical knockout against Dominic Brown at FM Production’s May event in Missouri.