Anthony Joshua will defend his world heavyweight titles against Carlos Takam after Kubrat Pulev was forced to pull out.
Joshua was due to face the Bulgarian in front of a crowd of 80,000 at the Principality Stadium in Cardiff on Saturday week.
But Pulev suffered a shoulder injury earlier this month in sparring and has been unable to recover.
As Pulev was the mandatory challenger for Joshua’s IBF belt, the governing body named Takam as next in line and he accepted the fight at less than two weeks’ notice.
The 36-year-old from Cameroon has won 35 of his 39 fights but lost his last world title challenge, against Joseph Parker last year.
He has won his last two fights by knockout, albeit against modest opposition.
Joshua was crowned world champion last year when he stopped Charles Martin in the second round to win the IBF strap.
Routine defences against Dominic Breazeale and Eric Molina followed before Joshua took on Wladimir Klitschko at Wembley six months ago.
The 2012 Olympic gold medalist climbed off the canvas to stop the heavyweight legend in the 11th round and add the WBA strap to his growing collection.
Boxing promoter Eddie Hearn said: “When the Pulev fight was announced I made a deal with Takam’s team to begin camp and be on standby for this fight. When I called them this evening they were overjoyed and good to go.
“It’s a difficult position for AJ having prepared meticulously for the style and height of Pulev, he now faces a completely different style and challenge in Takam – this hasn’t happened in his career before but he is ready for all comers on October 28.”