Yao Ming arrived in Chicago on Monday night and his workout is on schedule for Wednesday. He will have one workout partner during his 45-minute session: University of Oregon center Chris Christofferson, who will be giving away three inches to the 7-foot-5 Yao.

At least 22 NBA teams have committed to sending representatives to the workout. Yao will participate in shooting and half-court drills and will not do any full-court work.

The workout will be run by former NBA coach P.J. Carlesimo.

Last Friday, Yao's team -- the Shanghai Sharks -- said they would let him enter the NBA draft and play in the league after he was denied a chance to enter the draft in 2001. Yao will work out for NBA teams on May 1 and is expected to be one of the top two picks in the NBA Draft in June.

Li Yaomin, general manager of the Sharks, told the People's Daily newspaper in China that the Sharks hope Yao would go to a team that would make the NBA playoffs in two or three seasons. He said in the English online edition that he hoped whichever team chooses Yao would allow the Sharks to set up a training camp in the United States so their coaches and players could come every season. He also hoped the NBA team that drafts him would play games in Shanghai in return.

The 255-pound Yao led the Sharks to the Chinese Basketball Association title with a 3-1 series win over Bayi Rockets last week. Club director Bai Li told the People's Daily that Yao deserved a chance to play in the NBA after leading the Sharks to the title.

"It's exciting," NBA commissioner David Stern said Sunday night before the Detroit-Toronto game. "As a league, to see world-class players coming into our league from Latin America, Africa, Eastern Europe, Western Europe and Asia is an exciting thing for our league.

"And to think that there will be a generation that will grow up watching their countrymen play in the NBA, I think speaks well for our growth and development. I think it makes the competition in our league extraordinary tough, and it raises the level greatly.

"This was the year of the breakthrough for international players," Stern said.

Yao, who will turn 22 in September, is free of his Sharks' contract now that the 2001-02 season ended. His much anticipated return to the U.S. is expected to be April 30.

The NBA passed a rule that will forbid teams from watching agent-sponsored workouts the same week as the Chicago pre-draft camp June 5-8, meaning the workout has to be before the camp begins at the Moody Bible Institute.

Yao has been to the U.S. with his team and as an amateur, but this will be his first time as a prospective NBA player. Players like Fresno State's Melvin Ely and Alabama's Erwin Dudley went up against Yao in the World University Games semifinals in Beijing last August. Yao blocked a game winning shot by Ely and China went on to win the gold. Both Dudley and Ely said Yao is an immovable force in the middle when he gets the ball. They both said he simply couldn't be stopped from getting a shot off if he has it close to the basket but he can be denied the ball.

Now that Yao will be allowed to come to the U.S., he won't likely fall below the top two spots in the draft with Duke junior guard Jason Williams likely being the other choice. The concern among NBA teams was whether or not he would be available.

Meanwhile, at least one representative from each NBA team is expected to flock to Bologna, Italy, May 3-5 for the European final four championships to check out prospective NBA draft picks: Nikoloz Tskitishvili, Luis Scola, Bostjan Nachbar, Lazaros Papadopoulos, Mario Stojic and David Andersen.

Andy Katz is a senior writer at ESPN.com. He covers the NBA draft for ESPN.com and ESPN and will file periodic updates through the June 26 draft in New York. The Associated Press contributed to this report.