An unnamed cast member was forced to pull out of the show, presumably due to injury.
Seven won’t reveal which contestant until tonight’s show.
Laura Csortan, Demi Harman and Josh Thomas have all sustained injuries during rehearsals.
Contestants in the UK and US series have also been injured and in the Chinese version an assistant to a contestant drowned during a training session.
Boyer, 43, is also known for appearing on Gladiators as Thunder but says he is afraid of heights.
Source: News Limited