10:52 AM PT -- 7/1 -- Even though Giannis' knee is structurally OK ... it's still clearly too painful for him to play in Game 5.
The Bucks announced Thursday their best player will miss the key matchup with the Hawks.
No determination, meanwhile, has been made yet on his status for Game 6 or a potential Game 7.
1:24 PM PT -- Some great news for the Bucks -- ESPN's Adrian Wojnarowski is reporting there is no structural damage to Giannis' knee and his ligaments are "sound."
There is no timetable for his return ... but it's a huge sigh of relief for Milwaukee.
Bucks star Giannis Antetokounmpo terrifyingly hyperextended his knee Tuesday -- with his leg violently bending backward mid-game -- and there's now big concern the Greek Freak could be SERIOUSLY injured.
The 26-year-old, 2-time NBA MVP crumpled to the floor in pain during the 3rd quarter of Milwaukee's playoff game against the Atlanta Hawks -- and replays of the injury were tough to watch.