Willemse was born in Pretoria and played for the Lions and Bulls before moving to France to join Grenoble in 2014, switching his allegiances and eventually making his debut for Les Bleus in 2019.
As such, he has a unique perspective on the styles of rugby both teams are likely to play and says France cannot let South Africa's forwards get the upper hand.
He was a bruising, tough ball carrier himself, so he certainly knows a thing or two about fronting up.
He also believes Emmanuel Meafou is a key component of this strategy and has the potential to becoming a very important player for France going forward.
"The more experience he [Meafou] gets, I'd like to see him becoming the bully and becoming the classic enforcer on the field," he told AFP.
"I think he has everything he needs to get there. I'm really excited to see what he can do in the future."
Willemse will be at the stadium to watch the titanic contest on Saturday and there is no doubt in his mind about who he will be supporting.
"The French team, that's my teammates. That's the guys I played with. That's the guys I flipping chased dreams with, shared dreams with and achieved awesome things with them," Willemse said.
"There's no doubt in my mind. I've bled for the jersey. I've sacrificed for the jersey. So the French team is always going to be me."
Rassie Erasmus has named a familiar and formidable line-up to do battle with France in Paris on Saturday, on a day when Springbok captain Siya Kolisi will celebrate his 100th appearance in the green and gold.
France head coach Fabien Galthie has dropped his captain and named Gael Fickou as the leader of the matchday 23 to face the Springboks in Paris on Saturday.
Inter Milan reignited their Champions League charge on Wednesday night as Marcus Thuram made a long-awaited return from injury to inspire a tense 2-1 victory over Kairat Almaty at San Siro.
French publication Midi Olympique has crowned Pieter Steph du Toit the best player in the world, usurping France megastar Antoine Dupont.
