Joshua will defend his IBF crown in the fight against Klitschko but Hearn stated that there are still some formalities to be done before that can become official .
Klitschko will be formally announced at a press conference on Wednesday in London .
Joshua will defend his IBF crown in the fight against Klitschko , which will be formally announced at a press conference on Wednesday in London , but Hearn stated that there are still some formalities to be done before that can become official .