Updated

Retired basketball star Yao Ming, whose career was cut short by injury, has started classes at Jiaotong University, one of the top universities in his hometown Shanghai.

He joked to reporters Monday after his first day of classes that "the teacher showed me some mercy and did not leave me any homework."

The former Houston Rockets center, who retired four months ago because of chronic injuries to his left foot, is studying mathematics, English and modern Chinese history, hoping they will aid his business career.

He hopes to apply the knowledge to his business and public service ventures, which range from ownership of his hometown Shanghai Sharks professional basketball team to overseeing a multimillion-dollar charitable foundation.

Yao, 31, remains one of the most popular celebrities in China. Besides being named to eight NBA All-Star teams, he played in three Olympics and carried the Chinese flag during the opening ceremonies at the Beijing Olympics in 2008.

The 7-foot-6 center expanded the NBA's influence into the world's most populous country, creating lucrative merchandise sales for the league and TV ratings that skyrocketed whenever the Rockets played.