The knock on Marshall is that he's a bit slow-footed laterally and will have trouble guarding his counterparts.
Marshall's teammate John Henson, a 6-10 power forward and another Mavs target, was taken No. 14 by Milwaukee.
Dallas' No. 17 pick is just four away.
Another Tar Heel remains in center Tyler Zeller, who could be in play for the Mavs. Mississippi State power forward Arnett Moultrie and Iowa State small forward Royce White also remain.