He won the purse bid for his fight agaisnt Pablo Vidoz. Sosnowski has had fights in the states in the last 3 years as well as fights on Hennesey and Maloney cards.
You've got an answer for everything it seems... I only ask because after his fight against Vidoz he seemed to be celebrating with Hearn but wasn't sure of their arrangement.
He has done a few of his fights so they have a close relationship. Hearn knows he can sell him to the Polish community in the UK and get a big following. I think he is planning to match him with Harrison next.