Rafael Fiziev has pulled out of the UFC Rio main event, leaving Charles Oliveira without an opponent just weeks before fight night. The lightweight contest, scheduled for Oct. 11 in Rio de Janeiro, has been canceled due to Fiziev's injury. The UFC is exploring possible replacements to save the main event.Check out the X post below:Several fans took to X to react to the news. One fan called for Arman Tsarukyan to step in as a replacement for a rematch against Oliveira, writing:"PLEASE ARMAN PLEASEEEEEE!"Meanwhile, other fans wrote:"I don’t know if the UFC had anyone planned for Paddy [Pimblett], but that would surely be a fresh matchup at 155.""Dang, canceled instead of finding a replacement?""Nah, why do I feel like Dan Hooker might step in?""Am I the only one who wants to see Charles vs. Paddy?""[Renato] Moicano, Paddy or BSD [Benoit Saint Denis]?""Put Paddy in."Check out some of the fan reactions below:Fans react to the news of Charles Oliveira vs. Rafael Fiziev being canceled. [Screenshots courtesy: @ChampRDS on X]The setback halts Fiziev’s attempt to string together back-to-back wins. He returned to form in June with a decision victory over Ignacio Bahamondes. That victory marked his first success since a difficult run of losses to Justin Gaethje and Mateusz Gamrot.Oliveira is still expected to headline if the UFC can find a substitute. The Brazilian has not fought at home since defeating Kevin Lee in March 2020. 'Do Bronx' is coming off a first-round knockout loss to Ilia Topuria in June.Who can replace Rafael Fiziev to take on Charles Oliveira?Rafael Fiziev’s injury has forced him out of UFC Rio, and Charles Oliveira now needs a new opponent on short notice. The event is less than three weeks away, leaving the promotion to explore quick replacements for the Oct. 11 main event in Rio de Janeiro.One option is Mateusz Gamrot, who has long sought a chance to climb the rankings and would view Oliveira as the perfect opportunity.Another is Dan Hooker, returning from injury and rumored for a future fight. The pair have gone back and forth based on Oliveira's allegations of Hooker avoiding a fight against him. However, the Kiwi UFC star might not be ready in time to take on a short-notice challenge.A third possibility is Benoit Saint Denis, who recently fought in Paris and has the momentum and willingness to gamble on short notice. While fans are pushing for a fight against Paddy Pimblett, the UFC might have some major plans lined up for the proven draw. A short-notice fight might derail those plans.