The NBA organized a joint training camp for up-and-coming rookies every year in late May. The NBA invited about 60 new players to take part in the camp, putting them through a variety of physical and skill-based tests. Every year, scouts, general managers, and sometimes head coaches personally visited the camp and observed the training of the rookies.
If a team spotted a rookie that they liked, they would invite him to participate their team's rookie training. Rookies with potential got invitations from several teams.
In the past, many rookies who were predicted to get drafted early declined to take part in this joint rookie training or to only undergo the physical examination. They might be worried that the skill-based segment would expose their weaknesses.
