Not the next Yao Ming skipped the two-hour workout Tuesday evening as the NBA pre-draft camp opened. He also will bypass the games today, Thursday and Friday. He will be in town to take a physical. He will remain a curiosity.

China's Yi Jianlian goes up to shoot during his training ahead of the NBA pre-draft in US.Yi Jianlian is a known, a sure lottery pick June 28, possibly in the top five. But he also is an uncertainty of international proportions that won't be solved in the four days of intense scrutiny as 30 front offices and some coaches gather outside Orlando, Fla., the player who comes here with common doubt cloaked in official mystery.

Prospects from China must disprove doubts about adjusting from a league in which the competition is comparable to the lowest levels of Division I, less than in Europe and far below that of the recognizable school names that will rule the lottery four weeks from Thursday. More pressing, though, is the age issue.

NBA executives long ago accepted as unreliable the stated birthdates of Chinese prospects, aware of years of allegations of tampering by government officials trying to put players in an ideal light for international success. American teams then would begin tracking a supposed teenager in a junior tournament, unaware he might be two or three years older and in better position to play well -- and therefore have two or three fewer years left in his career in an obvious drawback to the organization that invests millions in his development.

Yi is said to be 20. Yao was 21 when he was picked first in 2002. Both are 7-footers, although Yao is that and then some, listed at 7-6. Both are from China.

Yao usually was delightful and charming when he joined the Rockets in a crush of media and marketing advances. Yi likewise appears welcoming of his new surroundings, speaking English and attending movie premieres while working out in Los Angeles in preparation for the draft.

But they are nowhere close to the same player. While Houston coaches had to plead with Yao to be more assertive and worked with him to find a necessary mean streak on the court, trying to push him into becoming an intimidating force inside, Yi is an aggressive forward who can handle the ball and gladly will drive to the basket and dunk on an opponent.

Sixty-two players are scheduled to participate during the four days, including point guard Bobby Brown, a two-time All-Big West Conference selection from Cal State Fullerton. Nineteen others -- Yi and the others expected to make up most of the top of the draft -- will attend only to take physicals.