Batum underwent an MRI exam Sunday, revealing the extent of the injury after leaving Saturday night's loss to the New York Knicks with the injury.
Batum has been ruled out of the Hornets' game against Philadelphia on Monday, and his return will be based upon his response to treatment on the Achilles, league sources said.
The Hornets are sure to be cautious with Batum. They're seven games out of the final playoff spot in the East, with only 12 games left in the regular season.
Batum is averaging 11.9 points, 5.5 assists and 4.9 rebounds a game for Charlotte this season.