The king is dead. Long live the king.
Donnie Nelson is no longer the general manager of the Dallas Mavericks. This is being reported as a mutual parting of ways, but whether Nelson chose to leave, was forced out or something in between is simply semantics.
It is not a stretch to argue that Donnie Nelson is one of the five most important people to the Dallas Mavericks franchise during his tenure. Dirk Nowitzki is the most important Maverick during that time. Luka Doncic will be the most important Maverick going forward. Mark Cuban is the most important non player simply because of who he is.