Since he was drafted by the Bucks, his age has been the subject of controversy. There is strong evidence that he was actually born in 1984 not in 1987 as first thought. It is widely thought that Chinese officials lied about his age so that he could play for more years in tournaments for younger players (under 19, or under 21). One Chinese basketball official admitted in 2006 that past Chinese junior teams included over-age players, and an American who played with Yi in China has said that players' ages were often changed. Yi has never commented on his age. In 2007 and 2008, Yi's date of birth was further scrutinized as being 27 October 1984, including a Chinese reporter discovering a high school enrollment form from 1997 that listed Yi as being born on 27 October 1984.