Thompson was a standout at the University of California, Los Angeles (UCLA), having an all-time scoring average of 15.6 points per game including 18.4 as a junior.

[1] Thompson declared for the NBA draft after the conclusion of his junior year, but withdrew to return for his senior season.

On November 4, 2005, the Suns assigned him to the Albuquerque Thunderbirds of the NBA D-League where he averaged 17.7 points and 7.7 rebounds in three games.

The Suns made him the first player of the season recalled from the D-League on November 26,[2] after Leandro Barbosa suffered a knee injury.

On March 10, 2006, Thompson underwent microfracture surgery on his right knee, causing him to sit out the rest of the season.

[7] On January 6, 2007, Thompson was signed to a 10-day contract by the Atlanta Hawks while forward Josh Smith recovered from a hernia operation.