Bochum defender Yahia and Siena forward Ghezzal pulled out of Saturday's training session, stirring worries over their World Cup prospects.

"I feel pain in my thigh and I don’t know the reason for that," Yahia was quoted as saying by Algerian media.

"I'm waiting for the scan results. I hope this injury will not prevent me from playing in the World Cup."

Ghezzal, who scored two goals during Algeria's qualifying campaign, sustained an ankle injury.

"I don't know the extent of the injury yet but I hope there is nothing serious," the 25-year-old said.

Algeria, who have reached the World Cup for the first time since 1986, open their campaign against Slovenia on June 13.

They will also face one-time world champions England and the United States in Group C.