Frank Maloney insists Tony Thompson has signed for a rematch with David Price on July 6 despite rumours to the contrary.
However, the London-based promoter revealed the American is not the easiest man to do business with.
"Everything Tony Thompson asked for he got and he has signed the contract for the rematch despite what people want to say," said Maloney.
"Tony is a great pro and knows how to work a fight. "But he can be very hard deal with when you are making an agreement to fight.
"He doesn't have a manager or promoter negotiating for him. Everything goes through himself and his wife.
"They have had me tearing my hair out, but signed the contract as soon as they received it."
Thompson stunned the unbeaten Price with a second round knockout in Liverpool last month.
He is expected to return to the UK early in May to fulfill media obligations in the lead-up to the rematch.