Heinze sidelined for three weeks
The 31-year-old was injured in a tackle with Lukas Podolski at the start of the second half of Argentina's 1-0 victory in a friendly against Germany in Munich on Wednesday.
"A scan has revealed a crack in the head of his fibula," Marseille said on their website. "Our medical staff believe he will not be available for three weeks."
Heinze is likely to miss both legs of Marseille's UEFA Europa League round of 16 tie with Benfica on March 11 in Lisbon and a week later at the Stade Velodrome.