Joel Embiid suffered a back injury late in his freshman season at Kansas and did not attend the NBA Draft combine in Chicago last week.
NBA teams do not have the medical reports of Embiid heading into Tuesday's draft lottery.
"The No. 1 issue is going to be the medical issue with him," a Central Division executive said. "There's no other issues really to deal with. With him not having taken the physical in Chicago, he's difficult to project. I don't see him falling out of the top three unless there's a medical red flag."
Embiid remains expected to be a high draft choice and gives personnel around the league confidence that he will contribute from day one.
"He could play tonight and be effective," a Northwest Division general manager said. "You cannot teach that reaction time, knowing when to block a shot, to go from help defense to getting back to your man, show and recover. It has to be natural because he hasn't been playing. basketball long enough for people to teach him that. Imagine when he is taught, with people who have that knowledge. He gives you the first move and then he gives you the countermove. Young guys don't do that. They give you the countermove and you say, 'You could have gone baseline before you went to the middle.' "