Former France star Marcel Desailly has suggested Didier Deschamps could use a half-fit Frank Ribery as a supersub as he fights to prove his fitness for the World Cup.
Ribery, 31, said on Thursday he was "optimistic" he could overcome his back injury in time for Brazil but has yet to take part in Les Bleus' World Cup preparations.
French media reported the Bayern midfielder had made a secret agreement with national team boss Didier Deschamps, 45, that he would withdraw from his nation's squad should he not be fit enough to play in this weekend's friendly with Jamaica.
Deschamps denied any such deal had been struck, and his assistant coach, Guy Stephan, 57, told RTL that Ribery's fitness was improving even if events on Friday could dictate his World Cup fate.
"It's progressing rather favourably," Stephan, who was also Deschamps' right-hand man at Ligue 1 side Marseille, said on Thursday. "He's rather well, but he's still not trained with the rest of the squad.
"All the most appropriate treatments have been carried out and are being carried out. There will be a full squad training session tomorrow. If all goes well, he'll be there. We have to wait until tomorrow. There's not much longer to wait. Tomorrow, we'll have an idea of what he's able to do on the pitch with a ball."
While Ribery will certainly be short of match fitness should he be able to even step onto the pitch, 1998 World Cup winner Desailly feels the ex-Marseille man could still have a role to play in Brazil.
"Didier can use him as a supersub," he told RTL. "I speak of using him as a supersub because he cannot be physically or mentally in shape for a World Cup -- to hope to be the best player at the World Cup. He can really be of service as a supersub. He's an explosive player in one-on-ones.
"If he's not ready for the first game, he could be for the second or third. There is no one else in the squad who can bring the explosiveness he does. The squad will construct itself in spite of him if France are successful.
"It has really weakened the squad, because there has been an injury to a key element. Now, I expect the boys to be closed off, that they stay within their bubbles, without worrying too much about the state of Franck Ribery. There is a life with and a life without him, and they absolutely have to apply that otherwise, automatically, it weakens the group."