The 27-year-old suffered a neck problem after a collision with Mustapha Yatabare while playing for his club in the 1-0 win over Guingamp on Saturday night.
Mandanda was withdrawn from the game, leaving his participation at the finals in Brazil under threat.
And on Sunday afternoon, the Stade Velodrome player confirmed on his official Twitter timeline that he will not take part in the French World Cup squad.
Mandanda had been selected alongside Tottenham Hotspur No. 1 Hugo Lloris and Mickael Landreau of Bastia in Didier Deschamps' squad for the World Cup.
And although the Marseille goalkeeper was expected to be an understudy to Lloris in Brazil, his injury absence will be a blow to the player and the squad.
Marseille club doctor Christophe Baudot is quoted as saying:
Steve has suffered a crack on his first cervical vertebra.
We are still to learn the length of time he needs to recover, he must go for further tests on Monday.
However, there is no neurological problem. He returned home in a medical transport after undergoing tests. He is wearing a neck brace, but he is fine.
Les Bleus are now likely to turn to Stephane Ruffier of Saint-Etienne from their reserve list.
Marseille president Vincent Labrune told French radio station RMC on Sunday that his sympathy was with Mandanda, as Reuters reported.
Labrune is quoted as saying: "I feel a great disappointment for the player, who is going to miss an important competition."
Mandanda rose through the ranks with the national team after playing for the France under-21 side before making his senior debut in a Euro 2008 warm-up match against Ecuador in May 2008.
Subsequently, the goalkeeper was named in Les Bleus' squad for the finals in Austria and Switzerland.
Mandanda began the 2010 World Cup qualifying campaign as the first-choice goalkeeper under then head coach Raymond Domenech before the emergence of Lloris.
The Marseille No. 1 was in the squad which traveled to South Africa for the 2010 World Cup finals, but did not feature in any matches.
Mandanda was also part of the France squad for the European Championships in Poland and Ukraine in 2012.
Mandanda currently has 16 caps for his country, and he has played for Marseille since 2007 following a trial with Aston Villa.