“Fabio has really captured the public’s imagination with his Cinderella type story and he’s an exciting fighter,” Mr Warren told BBC Radio Suffolk’s Wayne Bavin.
“Oleksandr is number one, best in the world, but he chose not to face Fabio.
“You can look at it anyway you like, but the fact of the matter is that Fabio was ready to go.”
Mr Warren said he always believed there was a “strong possibility” that Usyk would give up his title after Wardley had “shown what a danger he is”.
“This is an unbelievable story,” the promoter continued.
“Somebody who has never ever had an amateur fight; he’s just had a couple of white collar fights and he’s gone on to become champion.
“Not just Suffolk, but the whole nation should be proud of him.”
