The winger has urged players and supporters to rally behind the out-of-form striker ahead of their crunch World Cup 2014 qualifier
The form of the Real Madrid striker has come under intense scrutiny in his homeland, with his goal drought in internationals stretching back to a friendly against Estonia last June, in which he scored twice.
Speaking on Sunday to the football programme Telefoot, Ribery admitted that his international team-mate is experiencing some doubts over his contribution but is still putting effort in for the team.
"He doubts a little right now but he also works a lot for the team," the 29-year-old stated.
"He tries and he needs our supports and the support of the fans."
Ribery also spoke with relish at the prospect of facing la Roja, reminiscing about the 2006 World Cup clash between the sides, which saw the winger score and France go on to win 3-1.
"It is one of my best memories," he revealed.
"It was an important goal but it's a whole different game [on Tuesday]. I hope to play well and I hope we win.
"[Fifty games unbeaten] sure is a lot of games," he said of their opponents' current streak.
"But we played a great game there with a great second half and had a good result [a 1-1 draw in October]. We will play freely, without pressure. We hope to make it a good result."