Hudson was added to the roster before the Grizzlies' game Friday night against the Utah Jazz but was listed as inactive.
The Boston Celtics selected Hudson in the second round of last year's draft. He played in 16 games for Boston, averaging 1.4 points. The Celtics waived him Wednesday.
Hudson played at Central High and Southwest Tennessee Community College, both in Memphis, before attending Tennessee-Martin. He was second nationally in scoring during the 2008-09 season, averaging 27.5 points as a senior.