The Ukrainian will be in the stands at Tottenham Hotspur Stadium as Fury and Chisora fight for a third time with the WBC belt on the line.
Despite the fight being billed as a stepping stone to a meeting with Usyk in February or March, Fury said: “In a two-horse race, never underestimate anybody as anything can go wrong.
“We’ve seen many many times in the past when champions overlook opponents and think of other big fights, then the opponent goes in there and knocks the mother*****r out.
“For me, that will never happen because I train very hard and respect every opponent I face. I give 110% every time in gym. I’ve not had sex in six weeks. I want to come in like a ramping rabbit.”
The pair first met back in 2011 with Fury winning a unanimous points decision before being victorious inside 10 rounds at their second encounter three years later.
Fury and Chisora hinted they were ready to put on the most explosive opening round in heavyweight boxing history and revealed they had had a secret bet pre-fight, the forfeit for which will be revealed in the aftermath.
Fury pledged that Saturday night would be a “Christmas cracker” and that “whoever fights Derek Chisora is in for a f***king good fight”.
Chisora, meanwhile, said the fight had only been made possible by Fury, who rang him to set it up after it was overlooked by promoters Frank Warren, Bob Arum and Eddie Hearn.
And despite a double loss already to Fury, Chisora said he was determined to avoid a hat-trick of defeats.
“I was born in Africa,” he said. “What we know in Africa is we don’t give up. You only give up when you die. I’m so happy I’m still in the game.”