Anthony Joshua has warned he and Tyson Fury must both avoid "banana skins" to keep their planned undisputed title fight on track.
Joshua is expected to defend his IBF, WBA and WBO heavyweight titles against Kubrat Pulev in December while Fury is contracted to a third WBC title fight with Deontay Wilder.
The 30-year-old, who has agreed financial terms to two fights with Fury to decide the undisputed champion, said: "I listened to an interview the other week and [Fury] said that 'we need to make the fight and stop messing around'.
"But I thought we agreed the fight? Then he said if Dillian Whyte wins he's going to vacate the belt. I just think he's got a lot of things going on in his life that he says things that don't really add up.
"I respect him, I don't really know him but I respect him as a human. I could continue to talk but the best talking will be done in the ring. It's the best place to let our gloves do the talking."
Whyte lost his status as the mandatory challenger to Fury's belt with a knockout loss to Alexander Povetkin, although he has a rematch clause where he could gain vengeance.
Joshua has now warned Fury of the dangers of their undisputed title fight slipping away if their upcoming opponents spring a surprise.
"We've got to put them on an equal playing field because if I say 'I've got the bigger test' or 'he's got the bigger test', you never know what's going to happen," Joshua said.
"They're both banana skin fights. It's like 'get past this one then there's the big one next', so this one is just as important as the big one.
"When the time's right we'll fight. We're keen but I've got Kubrat Pulev first which is a mandatory defence, which I have to do. Once I get past that I'm a free agent.
"I'm going to say we'll fight next year but everything else that comes with it, I've just got to put to the back of my mind and just focus on Kubrat Pulev.
"Once I get past him, hopefully Fury will be the next one in line."
However, Joshua does have Oleksandr Usyk as his WBO mandatory challenger who expects a chance at the belt in 2021.
"Usyk has been the WBO mandatory challenger for more than one year," his co-promoter Alexander Krassyuk, who works alongside Eddie Hearn, told Sky Sports.
"He has agreed to let AJ versus Pulev happen, with regards that the winner fights him next. This statement is still solid.
"Our plan is A) beat Derek Chisora B) push AJ to comply with WBO rules or vacate the title C) defeat AJ (or any other WBO champion or contender and become the heavyweight champion. Simple and practical."