Adrien Rabiot has made a "huge mistake" in asking to be removed from the standby list for France's World Cup squad, according to coach Didier Deschamps.
The Paris Saint-Germain midfielder, who has six caps, was overlooked for the main 23-man selection, with Sevilla's Steven N'Zonzi preferred instead.
Rabiot - who previously demonstrated a reluctance to adopt a more deep-lying role for his country - was included among Les Bleus' group of first reserves for the tournament in Russia, but the 23-year-old made a request in writing to be de-selected.
Speaking at a media conference on Wednesday, shortly after the French Football Federation had expressed its surprise and disappointment at the move, Deschamps shed further light on the situation.
"It was not a letter sent, it was an email that arrived Monday late afternoon," he said. "I became aware of its content. Of course, Adrien signed it.
"I called him to have a confirmation that it was he who had sent this email. He did not answer me. I got confirmation from my manager. In the process, I warned my president of the content. I also warned the president of PSG because he is a PSG player.
"I was surprised of course. I can understand the disappointment, the immense disappointment, but to take such a position ... we are talking about a young player who for a while was in the French group. He excludes himself from the team.
"I dare to hope that through some decisions like this it will allow him to mature, to reflect. I am convinced that he made a huge mistake in taking such a position.
"He refuses his status as a reservist, to follow a program, and if there was a problem of being called as a substitute. It is his decision he assumes."
France are considered among the favourites to win the World Cup and must first negotiate a group that pits them against Australia, Peru and Denmark.