The Guinness PRO14 outfit are defending champions of the tournament and face a decisive Round 14 match against the Lions at Ellis Park, in Johannesburg, on Saturday.
The contest is effectively a straight shoot-out between the two teams with the winner booking a place in the semi-finals.
It has been a fine start to life in the Guinness PRO14 for the Cheetahs, who currently sit third in Conference A with three victories out of six.
It could have been even better for the Cheetahs but for Glasgow Warriors late try in Bloemfontein which denied the hosts a famous victory.
But now the Cheetahs’ attention is firmly set on the Currie Cup and a pivotal match against the Lions, something Duncan isn’t underestimating.
“This is an extremely important game for the Toyota Free State Cheetahs. We will be pushing as hard as we can to get results,” said Duncan.
— Toyota Cheetahs (@CheetahsRugby) October 9, 2017
“We aim to perform on the standard that we played in the Guinness PRO14,” added captain Torsten van Jaarsveld.
The Cheetahs have made three changes to the side that was edged out by the Warriors last weekend.
Raymond Rhule replaces Sergeal Petersen at full-back, Joan Coetzee returns in place of Tom Botha and there’s a starting berth for Nico Lee at outside centre, filling in for Francois Venter.
Meanwhile Lions coach Swys de Bruin is wary of the Cheetahs’ threats and believes they have gained a lot of confidence from their time in the Guinness PRO14.
He said: “They are a formidable side. They are an exceptionally well-balanced side who are very well organised in the set piece and those sevens players like Rosko Specman have made a big difference to them.
“I think they will come into this game having gained confidence in the Pro14.”
Toyota Cheetahs: Raymond Rhule, Rosko Specman, Nico Lee, William Small-Smith, Makazole Mapimpi, Ernst Stapelberg, Tian Meyer, Charles Marais, Torsten van Jaarsveld, Johan Coetzee, Justin Basson, Reniel Hugo, Paul Schoeman, Henco Venter, Oupa Mohoje
Replacements: Ox Nche, Jacques du Toit, Rynier Bernardo, Junior Pokomela, Shaun Venter, Ali Mgijima, Luther Obi
Golden Lions: Jaco van der Walt, Aphiwe Dyantyi, Rohan Janse van Rensburg, Harold Vorster, Courtnall Skosan, Jaco van der Walt, Ross Cronjé, Jacques van Rooyen, Robbie Coetzee, Jacobie Adriaanse, Andries Ferreira, Marvin Orie, Len Massyn, Cyle Brink, Kwagga Smith
Replacements: Malcolm Marx, Dylan Smith, Rhyno Herbst, Robert Kruger, Marco Jansen van Vuren, Ashlon Davids, Sylvian Mahuza
Match officials – Referee: Rasta Rasivhenge, AR1: AJ Jacobs, AR2: Stephan Geldenhuys, TMO: Johan Greeff
Guinness PRO14 Final 2018 Ticket Information: Fans can save up to 20% on selected tickets, and prices start at just €30 for adults and €5 for children, and be booked via www.ticketmaster.ie