Hatton said Brook has sparred with Rabchenko and won praise for his punching power .
Hatton helped train junior - middleweight Sergey Rabchenko of Belarus for a Saturday bout to open the Showtime broadcast against Detroit 's Tony Harrison .
Hatton , who helped train junior - middleweight Sergey Rabchenko of Belarus for a Saturday bout to open the Showtime broadcast against Detroit 's Tony Harrison , said Brook has sparred with Rabchenko and won praise for his punching power .