Veteran Centre Fäer Ficcou was appointed to start for France against Scotland in Paris on Saturday.
DuPont was ruled out for at least the rest of the season after ruptured the ligament in his right knee in his victory in Ireland.
Lux replaced DuPont after 30 minutes as France continued to slap Dublin’s host 42-27.
Fikou, 30, has not played for the Six Nations this year after breaking his thumb in club side race 92 early in the season.
“Essentially nothing has changed since our victory in Ireland. We had the same dynamics for the past six years. We had great success and losses,” coach Fabian Garchet said at a press conference on Thursday.
“We still promise to develop our players and be ambitious, and we have a great ambition and high standard to bring our French team to the top, no matter what happens.
“The results from last weekend have come to life, but our challenge this weekend puts the results questionable.”
The French victory over Scotland with four bonus points will give them the title in Paris.
England and Ireland are still competing to finish the top of the rankings.
France XV against Scotland:
Jean Baptiste Gross, Pete Mauvaca, Winni Atonio, Thibaut Fronti, Michael Gillard, François Cross, Paul Boudéhunt, Gregory Arlrudt (Captain), Maxim Luk, Roman Ntamac, Louis Biel Vibree, Yoram Moana, Fake Lamas
Alternatives: Julien Marchand, Cyril Bailu, Dorian Ardegeli, Hugo Aurado, Emmanuel Meehu, Oscar Jegou, Anthony Gerontz and Nornan Le Garreck.
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Six Snatch First Seven Countries Win in Paris
Ahead of the final round fixtures this weekend, we’ll relive three classic Six Nations games between France and Scotland.
– Overreaction: Does Marcus Smith cement the full back spot? Should Ireland reset?
– Tom Hamilton of Twickenham: The UK will work in Italy and maintain title hopes
– Can you replace Warren Gatland as Wales head coach?
– Watch: Relax some of the Six Nations classic games
– Six Nations and Women’s Six Nations: Full Fixture List