France will rest a number of key players for their final pool game against the USA.
Marsh is among those expected to be rested
The French booked their passage into the quarter-finals on Saturday with a 51-9 victory over Scotland - their third consecutive win of the tournament.
But coach Bernard Laporte revealed he would give a number of players a week off to prepare for the quarter-finals.
He said: "We decided to go for continuity in the team for the first
three matches but it will be nice to give Fabien Galthie and Tony Marsh a rest, for instance.
"Fabien has got a slight tweak in his ankle and Tony a slight problem on his Achilles' tendon but there is nothing to worry about.
"If a quarter-finals' berth had still been at stake, they would have played."
"But what that win [against Scotland] has done is allow me to have a look at some of the players who have not yet had a game.
"It is important that we find the right team to play whoever we meet in the quarter-finals, but we also need to ensure that everyone is fresh and ready."
Galthie's place looks set to be taken by Dmitri Yachvili, while Brian Liebenberg is likely to move into centre in place of Marsh.
Fly-half Gerald Merceron, wing Pepito Elhorga, lock David Auradou and flanker Sebastian Chabal are also in line to start.
David Bory, who has flown out to Australia as replacement for injured back Xavier Garbajosa, could be in contention for a starting place.