Springbok coach Allister Coetzee and captain Warren Whiteley expect a "huge onslaught" from France in the second Test on Saturday.
South Africa lead the three-Test series 1-0, after a 37-14 victory over the severely depleted Les Bleus in Pretoria last weekend.
However, the return of a host of key players - from the Top 14 finalists Clermont Auvergne (who won 22-16) and Toulon - means the Boks will face a far tougher Test in Durban.
The Bok skipper was under no illusion that last week's win gave them some advantage.
"We expect them to be improved," he said of a French team that shows eight changes and two positional switches from last week.
"They have named [a number of] players from the Top 14 Final - experienced players."
Whiteley said the Bok have focussed on ourselves, rather than put the focus on the French and the changes they have made.
"We want continuity," he said, adding: "We have focussed what we want to do and improve on the start we made last week.
"There will probably be more physicality.
"They are direct and their set pieces are strong.
"We realise it will be a bigger challenge."
Coetzee will hope for an improved performance on last week, to counter the French.
Coetzee labelled the Pretoria success "the start of a new chapter" while admitting that much-changed France are set to pose a much greater threat at Kings Park stadium.
"We know we will be up against a very well prepared French team in the second Test and are readying ourselves for that," he told reporters in the Indian Ocean port city.
"They want to bounce back and we want to continue with our processes. Both teams have a lot to play for.
"Although not perfect, I am pleased with our set pieces and expect a huge onslaught from the French in the scrums and line-outs."
Among eight starting changes by Les Bleus coach Guy Noves are two in the front row, one in the "engine room" and one in the back row, all designed to beef up the pack.
Skipper Guilhem Guirado, rested with six other squad members for the Pretoria Test after playing in the French Top 14 final the previous weekend, is recalled.
So are tighthead prop Rabah Slimani, lock Romain Taofifenua and flanker Kevin Gourdon, while more will be expected of star No. 8 Louis Picamoles than he achieved last weekend.
Coetzee also believes France will be more formidable at halfback for the second Test.
Flyhalf Francois Trinh-Duc and scrumhalf Baptiste Serin replace Jules Plisson and Maxime Machenaud, who failed to click at Loftus Versfeld stadium.
"Serin is a much bigger threat around the fringes and more of an attacking force in that he asks lots of questions," observed Coetzee.
"Trinh-Duc is an experienced player who makes good decisions and brings the players around him into the game.
"The French half-back pairing is going to be a much bigger threat than in Pretoria and a lot of their game revolves around the pair.
"Hopefully, we can apply pressure and it will be up to our players, particularly the loose forwards, to cut down their space and ensure they do not have time to make decisions."
The other two French alterations see South Africa-born Scott Spedding coming in at full-back and a first cap for outside centre Damian Penaud.
A son of former Les Bleus playmaker Alain, 20-year-old Penaud is rewarded for outstanding late-season form with Top 14 champions Clermont.
"We have the feeling, as with others, that he has talent. Now he must express it," said France coach Guy Noves.
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