Giannis Antetokounmpo could not plant or jump off his sprained ankle, sources told Adrian Wojnarowski of ESPN.
He has not yet been ruled out for game 5, with the Bucks down 3-1 in the series.
Antetokounmpo left the Bucks' game 4 win in the second quarter with the ankle injury.
Antetokounmpo reportedly wanted the team to tape up his ankle so he could return.
“He’ll get treatment through the night. We’ll just how he does over the next 24-48 hours," said Mike Budenholzer about his potential availability for game 5.