With Mitchell Robinson addition, Celtics fill biggest hole -- and weaken Knicks

The Boston Celtics have signed center Mitchell Robinson, a move that fills a key positional need for the reigning champions while simultaneously weakening their Eastern Conference rivals, the New York Knicks. Robinson was available because Knicks owner James Dolan was unwilling to push the team's payroll into the NBA's second apron luxury tax threshold. The addition gives the Celtics an experienced big man and represents a notable roster shift heading into the upcoming season.