In October 2011, Mormeck was signed to fight unified Heavyweight Champion Wladimir Klitschko on 10 December 2011 at Esprit Arena, Düsseldorf, Germany until Klitschko pulled out after having a kidney stone removed on 2 December 2011. The fight was postponed to 3 March 2012. In this fight, Mormeck attempted to be only the third cruiserweight champion to win a world title at Heavyweight, after Evander Holyfield and David Haye.
