According to Joan Guzman's manager, Jose Nunez, Floyd Mayweather Sr. has replaced Don House as Guzman's head trainer. The first bout for the new tandem will be Guzman's May 26, 2007 bout against Michael Katsidis (22-0, 20 KOs), to be broadcast on HBO. Guzman (27-0, 17 KOs) formerly held the WBO title at 122 pounds and now has the WBO title at 130, but he will be moving up once again to challenge Katsidis, who claimed the WBO interim lightweight title by defeating England's Graham Earl.