Dubois and Usyk, 38, fought in August 2023 with the Ukrainian winning via a ninth-round stoppage.
Dubois was promoted to IBF champion after Usyk vacated the belt last June shortly after beating Tyson Fury to become the first undisputed heavyweight boxing champion in 25 years.
The Briton was hoping to add to his 22 pro fight wins against Parker, having made the first defence of his belt by stopping Joshua in five rounds at Wembley Stadium in September.
But he was withdrawn from the bout on Thursday after being medically evaluated, with his place taken by Martin Bakole, who was dispatched by the Kiwi within two rounds.
“Daniel thought he would probably have done the same thing to Parker,” said Warren, 72.
“He’s very down and disappointed and he feels his moment was robbed. It happened at the wrong moment for him and cost him a lot of money and cost the fans a really good fight.”
Leave a Reply