Bayern Munich winger Kingsley Coman will miss "several weeks" after suffering a ligament tear to the same ankle that required surgery in February.
The France international was on the end of a crude late challenge from Hoffenheim defender Nico Schulz late in the first half of the Bundesliga season opener at Allianz Arena.
It was an unfortunate blemish for the reigning Bundesliga champions, who saw off Hoffenheim 3-1 in the league opener.
He was initially comforted by team-mates and had to be helped from the pitch by medical staff, having been unable to apply any pressure to his left foot.