France's Thomas Ramos, Peato Mauvaka ruled out of the Rugby World Cup

France have lost fullback Thomas Ramos and hooker Peato Mauvaka for the remainder of the World Cup in a mounting injury toll for Les Bleus in Japan.

Ramos twisted his left ankle during Wednesday's win over the United States in Fukuoka and will be replaced by La Rochelle back Vincent Rattez, who played the last of his two Tests against South Africa in 2017.

Mauvaka felt pain in the captain's run ahead of the U.S. game and a scan confirmed a hip muscle strain. He will be replaced by seven-Test Toulon hooker Christopher Tolofua.

France, who face Tonga in their third pool game in Kumamoto on Sunday, had already seen winger Wesley Fofana and prop Demba Bamba ruled out of the tournament due to injuries.

France coach Jacques Brunel said both Ramos and Mauvaka's recovery times exceeded 10 days, so he could not afford to keep them in the squad.

"It's a handicap for us," he told reporters in Kumamoto. "We hope that in the next match nothing will happen. We will try to get them to come as soon as possible."

Brunel also revealed that talented young scrum-half Antoine Dupont, rested for the laboured 33-9 win over the U.S., was hampered with back soreness but included him in the reserves for the Tonga clash.

Baptiste Serin, who came off the bench to help France seal victory late against the U.S., will start in the No. 9 shirt against Tonga.

Brunel said he had always planned to limit 22-year-old Dupont, who wore the No. 9 shirt in the opening win against Argentina, to only one starting appearance in France's first three pool matches.

"The team that we present today was the one we had planned for 10 days," said Brunel.

"Regarding Antoine, I do not think [his back] calls into question his participation in a possible quarterfinal.

"It is a small problem that must be managed. The proof is that he will participate this weekend."