Otherwise, practically every first-round prospect had to declare for the 2020 NBA Draft.
The NBA allows players to withdraw until 10 days before the draft (whenever that will be). The NCAA typically has an earlier withdrawal deadline for maintaining eligibility, though everything is in flux amid the coronavirus pandemic.
For now, here are all 205 early entrants (163 players from the American system and 42 international players):
Tulane guard Teshaun Hightower, who announced he was declaring for the draft and was since charged with murder, was not included.