In mixed martial arts (MMA), fighters can withdraw from scheduled bouts due to injuries or other unforeseen circumstances. When a fighter withdraws, the promotion, in this case the UFC, may seek a replacement opponent or cancel the fight altogether. UFC 313 is scheduled to take place in Las Vegas. - Dan Hooker withdrew from his scheduled fight against Justin Gaethje at UFC 313 due to a hand injury. - The Hooker-Gaethje fight was scheduled as a five-round bout and was considered a highly anticipated co-main event. - UFC officials have not yet commented on Hooker's withdrawal or announced whether Justin Gaethje will remain on the card. - Several fighters have volunteered to step in and fight Justin Gaethje as a replacement for Dan Hooker. - The main event of UFC 313 is a light heavyweight title fight between Alex Pereira and Magomed Ankalaev.