[2] In his first year at Kansas, Giddens earned All-Big 12 Conference Freshman honors while averaging 11 points per game.

[2][5] New Mexico hired head coach Steve Alford, who took a no-nonsense approach to discipline, and Giddens made a dramatic transformation.

He had worked out with the Celtics for three days, and received praises from head coach Doc Rivers,[8] who thought he could fight for minutes on the team right away.

But on behalf of his agent Aaron Mintz, Giddens declined to work out at the Celtics' minicamp in early July, because he had not signed a contract yet.

[11][12] On November 15, 2008, Giddens was assigned to the Boston Celtics' NBA Development League affiliate team, the Utah Flash.

On February 18, 2010, Giddens, Bill Walker and Eddie House were traded to the New York Knicks for Nate Robinson and Marcus Landry.

[24] On March 22, 2018, Giddens signed with Ferro Carril Oeste of the Liga Nacional de Básquet in Argentina.