Prop Luan de Bruin, loose forward Boom Prinsloo and flyhalf Elgar Watts all sustained injuries against Griquas last weekend.
Young prop Rudolph Botha would replace De Bruin, with Neill Claassen coming off the bench as back up for Prinsloo. Willie du Plessis would resume the role as flyhalf role after he had played second fiddle to Watts for the game against the Pumas in round one.
“We have been affected by a couple of injuries, but we believe we have adequate depth and that we are as strong as possible for the game against the Sharks,” Duncan said on Wednesday.
“We know it is going to be tough and we have prepared for it likewise.”
In the back line, Duncan included newcomer Clayton Blommetjies, who would play in his first Currie Cup game for the Free State since he relocated to Bloemfontein from the Blue Bulls earlier this season.
He had proven his worth at training and Duncan believed he had done enough to get a bid in the run on side.
“We are giving AJ Coertzen a rest and have decided to give Clayton a chance at fullback. He has put in the hard yards on the training field and we believe he is ready.
“This is a good chance for him to stake a claim as a regular inclusion in the competition.”
Among the replacements were a host of unfamiliar faces. Prop George Marich, loose forward Vincent Jobo and flyhalf Pieter-Steyn de Wet would all make their Currie Cup debuts if they came off the bench.
Cheetahs team: Clayton Blommetjies, Rayno Benjamin, Francois Venter, Joubert Engelbrecht, Raymond Rhule, Willie du Plessis, Sarel Pretorius, Jean Cook, Neill Claassen, Tienie Burger, Francois Uys, Carl Wegner, Rudolph Botha, Torsten van Jaarsveld (captain), Kevin Stevens.
Replacements: AJ le Roux, George Marich, Henco Venter, Vincent Jobo, Shaun Venter, Pieter-Steyn de Wet, JP du Plessis.