The event was expected to be headlined by a UFC Featherweight Championship bout between current champion José Aldo and top contender Conor McGregor. On June 23, it was reported that Aldo suffered a rib fracture and could pull out of the bout in light of the injury.A day later, the UFC received official medical confirmation from several doctors that Aldo did not suffer such injury. Following a review of the scans, it was determined that the champion suffered a bone bruise to his rib and cartilage injury during training. Aldo had expressed that he had every intention of fighting. Despite that, the UFC announced a contingency plan that would have Chad Mendes face McGregor for the interim championship in the event that Aldo could not compete. On June 30, it was confirmed that Aldo indeed pulled out of the bout and that the interim championship bout would take place at this event. UFC president Dana White said the reason for the interim title, in this case, had to do with Aldo's history of pulling out of title fights, despite having defended it only 9 months earlier at UFC 179. The bout remained the event headliner. On July 1, photographs of Aldo's scans were released and indicated that he had indeed suffered a fractured rib. On July 10, White claimed that Aldo did not have a broken rib as "every x-ray he sent out was of an old injury". He reaffirmed that Aldo had a "bruised rib and cartilage" and that the biggest problem was the weight cutting process being complicated by the injury. The co-main event featured a UFC Welterweight Championship bout between current champion Robbie Lawler and top contender Rory MacDonald. Their first fight at UFC 167 ended in a split decision victory for Lawler. The event took place during the UFC's annual International Fight Week.