[1] Washington transferred to AZ Compass Prep School in Chandler, Arizona during his junior season.

[5] He decommitted on March 11, 2021, nine days after head coach Greg McDermott recalled telling his players, "I need everybody to stay on the plantation.

The Grizzlies traded Washington and Walker Kessler to the Minnesota Timberwolves on draft night for Jake LaRavia.

On October 2, 2022, Washington made his preseason debut, registering eight points along with three rebounds and one assist in a 134–96 win against the San Antonio Spurs.

[13] On July 12, he was traded again, this time to the Oklahoma City Thunder, along with Usman Garuba, Rudy Gay and a 2026 second-round pick, in exchange for Patty Mills.