The boxing and MMA superstars collide in a crossover clash next Saturday in Saudi Arabia.
And according to Ngannou, they will box in a 24-foot ring which is the largest it can be.
But Fury hit back to deny requesting the larger ring when face to face with the ex-UFC champion.
Ngannou told TNT Sports: “I prepared to make him move less. And I know that he asked for the biggest size of the ring possible.”
Fury, 35, responded: “I didn’t ask for any ring. I’ll fight you in a phone box, no problem.”
Ngannou, 37, replied: “OK So, you didn’t ask for a 24-feet ring?”
Fury said: “I didn’t ask for any size ring. I’ve not even spoke to the guys. I don’t get involved in the business.
“But the championship ring is only 20 feet. So, if they’ve asked for a 24-foot, let’s do it in a 20-foot. Easy.”
Ending the argument, Ngannou said: “They asked for 24.”
FREE BETS – BEST BETTING OFFERS AND BONUSES NEW CUSTOMERS
Fury heads into the fight full of confidence and even gave away his game plan to Ngannou’s face.
He said: “I’m gonna knock him out inside six rounds. And shall I tell you how I’m going to do it?
“Get on the front foot, high arm, sticking him with a punishing jab, 19, 20 stone in the face, boom, boom, boom, bust him up, swell his eyes out, and then feint, slip, bang! KO.
“On the front foot, not running away. On the front foot, hand-eye, let him hit the shoulder, slip, slip, bang, slip, slip, bang. Down in a heap.
“Listen, no one can take my power. Nobody. These heavyweights don’t have a chance.”