Milwaukee Bucks star Giannis Antetokounmpo is questionable for Game 4 of the Eastern Conference semi-finals against the Miami Heat due to a right ankle sprain.

The top-seeded Bucks trail 3-0 and are facing a stunning series sweep at the hands of the Heat in the NBA playoffs heading into Sunday's crucial clash at Walt Disney World Resort.

Antetokounmpo rolled his ankle in the first half of Milwaukee's 115-100 Game 3 loss to Miami in Orlando, Florida on Friday.

The reigning MVP still posted 21 points, 16 rebounds and nine assists for the struggling Bucks.

No NBA team have overturned a 3-0 series deficit as the Bucks – eyeing their first championship since 1971 – fight to stay alive in the postseason.