Morris was diagnosed with transient cervical neurapraxia and will be limited to non-contact basketball activities.
Morris has missed Washington's past three games. The injury occurred when he was knocked on the chin during a game against the Los Angeles Lakers on Dec. 16 and was reaggravated on Dec. 26 at Detroit.
An MRI had revealed no significant damage, so Morris saw a back specialist, Dallas-based Dr. Andrew Dossett, who diagnosed the injury.
The team said Morris is expected to be cleared to return to full basketball activities after six weeks.
Morris is averaging 11.5 points and 5.1 rebounds in 34 games for the Wizards this season.