Unbeaten and second-ranked light-heavyweight contender Daniel Cormier will replace injured Alexander Gustafsson as champion Jon Jones' opponent on Sept. 27 at Las Vegas, the Ultimate Fighting Championship announced Wednesday.
Gustafsson injured a knee and won't be able to keep the date for his rematch with Jones, who won their first fight by unanimous decision.
Cormier (15-0) and Jones have traded barbs on social media and in the media since Cormier moved into the light-heavyweight division.
Cormier, a two-time Olympian and former wrestler at Oklahoma State, has UFC wins over some big-name fighters, including Dan Henderson, Frank Mir, Roy Nelson and Patrick Cummins.
The Sept. 27 title fight will headline UFC 178 at the MGM Grand.