Desailly issued a statement on behalf of the France team on the eve of the election that sees hard right leader Le Pen challenge Conservative incumbent Jacques Chirac for the presidency.
He did not refer directly to the anti-immigrant National Front candidate Le Pen, who stunned France by coming second to Chirac in the first round of voting in April.
But the statement denounced "attitudes that endanger democracy and freedom".
The France football team have dedicated their recent triumphs to the diverse elements in the country - and their statement was clearly designed to deliver a blow to Le Pen's election campaign.
Desailly's statement read: "The players in the French team, from diverse origins...are unanimous in condemning resurgent ideas of racism and exclusion," the sports newspaper L'Equipe quoted the Ghanaian-born captain Desailly as saying on its website.
"They view attitudes that endanger democracy and freedom as intolerable and indefensible, particularly in a multi-ethnic and multi-cultural France."
The condemnation came after Real Madrid's star midfielder Zinedine Zidane, hero of the 1998 World Cup-winning team and an icon for France's big North African immigrant community, called for a huge vote against Le Pen on Sunday.
The multi-racial team that clinched the World Cup on home soil four years ago was trumpeted as a symbol of a "rainbow nation" of ethnic tolerance.
But Le Pen has scoffed at that and once complained foreign-born players did not know the French national anthem.
"I find it artificial to have foreign players come and play in France and call them the French team," the 73-year-old former paratrooper said in 1996.
"Most French players don't even know, or don't want to sing, the Marseillaise."