Ball, the third overall draft pick of 2020, is also dealing with right wrist soreness.
It's the third time this season that Ball has injured the same ankle. He missed the first 13 games of the season after spraining it the first time and played in just three games before spraining it again Nov. 16 when he stepped on a fan's foot against Indiana. That time he missed 11 games with the injury.
This time he injured his ankle in Wednesday's win at Houston.
After losing eight of nine, the Hornets have won two straight, their first win streak since the end of November. At 13-34, they are next-to-last in the Eastern Conference.
"Obviously, Melo is our star player," Hornets guard Terry Rozier said. "We definitely need him. It's definitely been our story all season, so we just try to work with what we've got and play the best basketball that we can.
The Associated Press contributed to this report.