Several members of Gregor Townsend's squad - including Darge - played for Glasgow Warriors when they pulled off their historic URC final triumph over the Bulls in Pretoria in June.
Blair Kinghorn also enjoyed notable success last term as part of the Toulouse squad that won a Top 14 and Champions Cup double.
Darge believes that success at club level have given the Scotland players a renewed sense of confidence when they take on the best in the world.
"It is a good thing that we've had the experience of playing South Africa," said the back-row man.
"A lot of the group have had the experience of playing them now, so I have a bit of a better idea of what's coming.
"The other thing that helps is the sort of form that the players in this group have been in away from here. The results they've got and obviously the club's successes and the form that we've been in with Scotland as well means that we'll go into it with a bit of belief.
"It gives you a bit of belief that you can go out and win those big games (at club level). It's not just Glasgow, obviously Blair coming out with experience of winning the double, and others. That definitely has an impact."
Darge is relishing the chance to face South Africa despite the 18-3 loss in Marseille in September 2023.
"You're always excited to play for Scotland and nerves come into it a little bit, but it's mainly excitement," said Darge, looking towards Sunday's match.
"It's an opportunity to play the two-time world champions. Everyone came in on Monday just excited to get into it.
"It was obviously a really tough game 14 months ago. The way they play against you puts you under a lot of pressure, and tests your skills.
"I think we learnt a lot from that game, we'll refer to it a little bit this week but both us and them have played a lot of rugby since then, so we'll not spend too much time on it."
Darge skippered Scotland alongside Finn Russell during this year's Six Nations but the back-rower has now reverted to being a vice-captain after his Glasgow team-mate Sione Tuipulotu was promoted to the role of captain last month.
"It's been grand," he said of change of captaincy.
"Me and Sione are obviously good mates, played a lot of rugby together over the last few years and I think he'll do a really good job.
"He's always been one of the main leaders in our team. Anything that I can do to support him, I'll do."