The moment that Daniel Cormier decided to drop to light heavyweight from heavyweight, the former Oklahoma State wrestling star and 2008 U.S. Olympic wrestling captain put his sights squarely on champion Jon Jones.

Cormier got his wish on Wednesday when he was chosen to replace Alexander Gustafsson opposite Jones in the light heavyweight championship bout that will headline UFC 178 on Sept. 27 at the MGM Grand in Las Vegas.

Gustafsson, who nearly defeated Jones last year in an epic battle at UFC 165 in Toronto in one of the great matches in UFC history, tore the meniscus a knee in training that forced his withdrawal.

There is no extent of the severity of the injury or how long he'll be out. UFC CEO Lorenzo Fertitta said Gustafsson was hurt while training in Sweden. He said because of the time difference between Sweden and Las Vegas, it's been difficult for him to get information from Gustafsson's camp.

Fertitta said Cormier was eager when he offered him the bout. Cormier told MMA Fighting last month that he might need surgery on his injured knee, but Fertitta said that is no longer the case.

He said Cormier's right knee healed through rest and rehabilitation and that surgery is no longer required.

"He is very excited about the fight and this opportunity and he's eager and ready to go," Fertitta said.

Fertitta said there was no consideration given to postponing the bout and waiting for Gustafsson to heal. Jones wanted to fight and Cormier was available to provide a top-level opponent.

Cormier is ranked No. 2 at light heavyweight behind Jones, the champion, and Gustafsson, the No. 1 contender.