The Wizards also have waived center Sean Marks, and Thursday's moves allow the team to cut its roster to 15 players.
Morrison averaged five points and two rebounds in five preseason games with Washington. He was drafted with the No. 3 overall pick by the Charlotte Bobcats in 2006 after starring in college at Gonzaga.
The 6-foot-8 forward has played in four NBA seasons, two with Charlotte and two with the Los Angeles Lakers, with career averages of 7.5 points and 2.1 rebounds.
Marks has played for five teams since entering the league in 1998. He didn't appear in any games for the Wizards this preseason.