Antetokounmpo played less than a minute before suffering the injury.
The two-time MVP had already missed six games earlier this month due to left knee soreness and could now miss more time with this right ankle sprain. He initially suffered a left knee sprain in late March but missed only one game before returning to the floor.
He remains one of the top players in the league when healthy, entering the day with averages of 28.5 points, 11.4 rebounds and 6.0 assists per game.
Extended absences were previously rare for Antetokounmpo, who never missed more than 10 regular-season games in any of his first seven years in the NBA.
The 26-year-old did deal with an ankle injury during the 2020 postseason, limiting the forward as the Miami Heat eliminated the Bucks in the second round of the playoffs.
Milwaukee obviously takes a step back whenever Giannis is unavailable, putting pressure on other players like Khris Middleton and Jrue Holiday to take on bigger roles offensively. Bobby Portis and Thanasis Antetokounmpo should also see extra minutes until the superstar is back to full strength.