Yahoo Sports' Chris Haynes reported seeing Antetokounmpo "severely limping" after Game 3, though the forward said the ankle wasn't an issue while playing.
Antetokounmpo's importance to the Bucks largely goes without saying. He's the reigning NBA MVP and likely headed for his second straight nod.
The 25-year-old averaged 29.5 points, 13.6 rebounds and 5.6 assists during the regular season for Milwaukee, which secured the No. 1 seed in the Eastern Conference.
The Bucks' front office has done a great job of strengthening Antetokounmpo's role within both their financial means and their status as a non-marquee free-agent destination. Milwaukee can feasibly throw out four shooters to space the floor to free up the paint for the Greek Freak.
Of course, the obvious drawback to effectively building the roster around one player is that things can quickly unravel when that one player is unavailable.
Last year, the Toronto Raptors eliminated Milwaukee in the Eastern Conference Finals in large part because they smothered Giannis at all times and put the onus on the rest of the team.
With the Bucks down 3-0 to the Heat in the Eastern Conference Semifinals, this injury could pose a significant threat to their title hopes. If Antetokounmpo were to miss the game or play at less than 100 percent, Milwaukee could be in serious trouble.