Overview

• The heavyweight bout was pulled Thursday after Mohammed Usman withdrew, initially described as an injury.
• Valter Walker wants to stay on Saturday’s card in Rio de Janeiro as the promotion explores a replacement, with no new opponent announced.
• Viana later reported Usman was flagged for elevated testosterone from a September sample, a claim not confirmed by the UFC.
• The canceled matchup drew interest as a meeting of Johnny Walker’s brother and Kamaru Usman’s brother.
• Walker entered on three straight heel‑hook wins in pursuit of a fourth, while the Oliveira–Gamrot main event and Figueiredo–Jackson co‑main remain intact.