Marc Lièvremont has also chosen to bring in Montpellier flanker Fulgence Ouedraogo ahead of former teammate Louis Picamoles in order to counter the pace of the young Welsh back row.
Lièvremont said: "I'd said before that Fulgence is an interesting option because of his link play against the speed and playmaking ability of the Welsh.
"And even though David Marty played very well off the bench against England, I wanted to have a whole half-back pairing on the bench. I feel good about Jean-Marc.
"He's been training for a month, he's not there by chance. I like him and I have complete confidence in him."
Lièvremont also confirmed that Doussain would replace Yachvili if the Biarritz scrum-half had to come off, rather than François Trinh-Duc coming on at fly-half and Morgan Parra switching to nine.
"Making Morgan move back to scrum-half would mean completely changing the half-backs. Morgan has worked really hard at ten for the last month. We've worked all week with Jean-Marc at scrum-half."
15. Maxime Médard - Toulouse
14. Vincent Clerc - Toulouse
13. Aurélien Rougerie - Clermont Auvergne
12. Maxime Mermoz - Perpignan
11. Alexis Palisson - Toulon
10. Morgan Parra - Clermont Auvergne
9. Dimitri Yachvili - Biarritz
1. Jean-Baptiste Poux - Toulouse
2. William Servat - Toulouse
3. Nicolas Mas - Perpignan
4. Pascal Papé - Stade Français
5. Lionel Nallet - Racing Métro
6. Thierry Dusautoir - Toulouse
7. Julien Bonnaire - Clermont Auvergne
8. Imanol Harinordoquy - Biarritz
16. Dimitri Szarzewski - Stade Français
17. Fabien Barcella - Biarritz
18. Julien Pierre - Clermont Auvergne
19. Fulgence Ouedraogo - Montpellier
20. François Trinh-Duc - Montpellier
21. Jean-Marc Doussain - Toulouse
22. Cédric Heymans - Bayonne