Last night, news broke that Rafael Fiziev had been forced out of his scheduled UFC Rio de Janeiro fight against Charles Oliveira due to an injury. As the promotions reportedly explore a potential replacement to salvage the card, one top 10 lightweight has stepped up, setting the MMA fandom abuzz.Reacting to a social media post about Fiziev dropping out of the event, No.8-ranked lightweight contender Mateusz Gamrot threw his name in the mix, writing:"I'm ready and hungry to jump in!! Come on. @ufc"Check out Mateusz Gamrot offering to replace Rafael Fiziev at UFC Rio de Janeiro below:Naturally, fight fans had a lot to say about the development, with many flocking to social media to express their thoughts and opinions.@DudesMMA_ wrote:"That would be perfect."@Sportautist opined:"Everybody smells blood rn and wanna fight concussed Oliveira. Like fr Oliveira, should not even be having a fight."@Pullen304 chimed in:"Charles f**ks you up bro."Check out a few more reactions below:Screenshots courtesy: @gamer_mma on Instagram'Gamer' is 4-1 in his last five outings, most recently earning a unanimous decision win over Ludovit Klein at UFC Vegas 107 in May. He holds victories over the likes of Rafael dos Anjos, Fiziev, and Arman Tsarukyan, who himself holds a win over Oliveira. A win against the Brazilian may catapult him into the lightweight title mix.'Do Bronx', meanwhile, is coming off a first-round KO loss to Ilia Topuria at UFC 317 in June. Many believe that making a quick turnaround in October could prove counterproductive for the former lightweight champion's career.Charles Oliveira is undeterred by Rafael Fiziev pulling outWhile Charles Oliveira has reportedly lost his dancing partner for UFC Rio de Janeiro, he remains composed and committed to training, almost as if he still intends to make the walk to the octagon on the scheduled date.After news broke on 'Ataman's' injury and his withdrawal from the event, the Brazilian shared a video of himself and his teammates engaging in an intense strength and conditioning drill with the caption, with the caption:"Focus on the mission." [Translated from Portuguese to English via Instagram]UFC Rio de Janeiro is scheduled to take place on Oct. 11, Farmasi Arena in Rio de Janeiro, Brazil. However, now having seemingly lost its main event, the fate of the card remains unclear.