LOS ANGELES -- The UFC's first pay-per-view event of 2025 underwent a major change Friday, as lightweight title challenger Arman Tsarukyan was forced out of Saturday's UFC 311 at Intuit Dome in Inglewood with a back issue.

UFC lightweight champion Islam Makhachev (26-1) will now defend his title against Renato Moicano (22-3), who was scheduled to fight Beneil Dariush on the card. UFC CEO Dana White announced the change on Friday morning, during the official weigh-ins. According to sources, Tsarukyan, 28, was on pace to make weight but suffered from back spasms.

"[Tsarukyan] informed us that he was experiencing significant back pain," White said. "Due to the injury, he feels like he is not healthy enough to compete. Stepping in to face him is Renato Moicano."

Makhachev, who is seeking the fourth defense of his 155-pound championship, told ESPN in a statement he didn't mind the last minute change.

"Champions do not choose opponents," Makhachev said. "As long as there's someone who can make 155, I'll fight anyone."

Moicano (20-5-1) is on a four-fight win streak and ranked No. 10 in the division. He is coming off a second-round stoppage of Benoit Saint-Denis in September.