event. However on October 9, it was announced that Esparza was pulled due to undisclosed reasons. Ribas was rescheduled against former Invicta FC Atomweight Champion Michelle Waterson at UFC 257. A middleweight rematch between Omari Akhmedov and Marvin Vettori was briefly linked to the event. The pairing met previously at UFC 219 in December 2017, when they fought to a majority draw. On October 13, it was announced that Akhmedov pulled out due to undisclosed reasons and was replaced by former Strikeforce Middleweight Champion Ronaldo Souza. In turn, Vettori was removed from the contest to serve as a replacement for the main event of UFC on ESPN: Hermansson vs. Vettori a week earlier. Kevin Holland, whom Vettori replaced due to a COVID-19 positive test, was rescheduled to face Souza at this event. A featherweight bout between Billy Quarantillo and Gavin Tucker took place at this event. The pairing was previously scheduled to meet at an event on April 25 that was cancelled due to the COVID-19 pandemic. Renato Moicano and Rafael Fiziev were expected to meet in a lightweight bout at UFC on ESPN: Smith vs. Clark. In turn, Moicano pulled out after testing positive for COVID-19 and the bout was rescheduled for this event. Andrea Lee was expected to face Gillian Robertson in a women's flyweight bout at this event. However, Lee pulled out in early December due to a broken nose and Robertson was rescheduled to face Taila Santos at UFC Fight Night: Thompson vs. Neal. A week before the event, several fights were impacted by the COVID-19 pandemic: A women's strawweight rematch between former Invicta FC Strawweight Champion Angela Hill and Tecia Torres was expected to take place at this event. The pairing met previously at UFC 188 in June 2015, when Torres won by unanimous decision. However, Hill tested positive on December 6 and was removed from the bout. Torres faced promotional newcomer Sam Hughes. Karl Roberson and Dalcha Lungiambula were expected to meet in a middleweight bout at this card, but were eventually rescheduled for the following week's event due to Roberson's positive test. Dwight Grant also tested positive for COVID-19 during fight week and had to pull out of his welterweight bout against Li Jingliang. A replacement wasn't able to be found and therefore Li was removed from the event. Two days before the event, Jared Vanderaa also pulled out of the event due