Nigerian born, welterweight champion Kamaru Usman has issued a stern warning to his next challenger, American’s Jorge Masvidal ahead of their huge welterweight fight at UFC 251 this weekend. Masvidal, nicknamed Gamebred, replaced Usman’s original opponent Gilbert Burns, who withdrew from the fight after he tested positive for Coronavirus. The fight will be held on Saturday night, July 11, at UFC Fight Island in Abu Dhabi And ahead of the showdown, ‘The Nigerian Nightmare’ Usman has …