The Nevada Athletic Commission also appointed U.S. judges Adalaide Byrd, Jerry Roth and Cathy Leonard to keep the scores.
Collazo, former world champion and current international WBA king has 35-5, 18 KO’s, while Khan, also formerworld champion has 28-3, 19 KO’s.
The battle will take place before the main fight of between Marcos Rene Maidana and Floyd Mayweather Jr., who will have Tony Weeks as the third in the ring, with Dave Moretti, Burt Clements and Michael Pernick, in charge of the score cards.
Gilberto Jesus Mendoza will be the WBA supervisor of both fights.