Griquas coach Pote Human has made four changes to his line-up for their second-leg promotion/relegation match against the Pumas in Nelspruit.
The Kimberley-based side travel to the Mbombela Stadium without stalwart lock Jaco Nepgen, who suffered a knee injury in the first-leg home clash.
Griquas though will instead have the scrumming power of veteran prop Lourens Adriaanse who is cleared to play after injuring a stomach muscle.
"It is a huge relief that Lourens can play, but at the same time a big loss that Jaco can't," Human said on Tuesday.
"He has been one of our stalwarts especially in the lineouts and driving mauls and he will be sorely missed. We trust that Patrick O'Brien will prove his worth in this all important game."
Human added: "We cannot afford to lose the game to the Pumas and, therefore, our discipline has to be top notch."
"We gave away silly penalties last week and they capitalised on that. If we don't limit our infringements it can cost us dearly."
Griquas: 15 Gouws Prinsloo, 14 Willie le Roux, 13 Jean Stemmet, 12 Howard Mnisi, 11 Rocco Jansen, 10 Francois Brummer, 9 Jacques Coetzee, 8 Carel Greeff, 7 RJ Liebenberg, 6 Burger Schoeman, 5 Patrick O'Brien, 4 Ligtoring Landman, 3 Lourens Adriaanse, 2 Ryno Barnes (capt), 1 Steph Roberts.
Replacements: 16 Matt Dobson, 17 Janro van Niekerk, 18 Nick Schonert, 19 Marnus Schoeman, 20 Marnus Hugo, 21 JP Nel, 22 Nico Scheepers.
Date: Friday, October 25
Kick-off: 19:10 local (18:10 BST, 17:10 GMT)
Venue: Mbombela Stadium, Nelspruit
Referee: Craig Joubert
Assistant referees: Sieg van Staden, Cobus Wessels
Television match official: Johan Greeff