- UFC 311 was to be headlined by Islam Makhachev vs Arman Tsarukyan
- The main event has now been changed just 24 hours before the title fight.
The main event of UFC 311 has changed dramatically just 24 hours before Saturday's card in California.
Lightweight champion Islam Makhachev was due to defend his title against Armenian Arman Tsarukyan.
But Tsarukyan has now pulled out of the title fight due to a back injury.
The UFC has wasted little time in finding a replacement, with Brazilian Renato Moicano stepping in to challenge Makhachev for lightweight gold.
UFC president Dana White announced the news Friday in a video on social media. White said: 'At around 1am we received a call from Arman Tsarukyan who informed us that he was experiencing significant back pain. Due to the injury, he feels he is not healthy enough to compete. Therefore, he is out of the fight.
'To face Islam Makhachev for the title will be Renato Moicano. He considered the championship weight to be prepared as a backup in case something happened, and when we spoke to him this morning, I can tell you that he wants this fight.
Islam Makhachev (left) has been assigned a new opponent after Arman Tsarukyan (right) withdrew from his main event at UFC 311.
Makhachev will now defend his lightweight title against Brazilian Renato Moicano (pictured)
“And when I called upon Islam, Islam said, 'Brother, I am the champion. “I don't care who it is, I'll fight anyone.”
Moicano, 35, has an MMA record of 20 wins, five losses and one draw.
He has won six of his last seven fights, five of those victories coming at distance.
But he faces a tough challenge to overcome Makhachev, who is widely considered the number one pound-for-pound fighter on the planet.
Makhachev has only lost one of his 27 professional fights and is currently on a 14-fight winning streak.