T he Mavericks hired Rockets executive Gersson Rosas as general manager, filling a spot that technically had been vacant since Don Nelson left the franchise eight years ago. It had been informally handled by Nelson’s son, president of basketball operations Donnie Nelson. The Jazz signed free agent guard John Lucas III, who played in a career-high 63 games last season with the Raptors. The Celtics signed center Vitor Faverani of Brazil, who played in Spain last season, and point guard Phil Pressey from Missouri. The Raptors signed D.J. Augustin to a one-year deal so he can back up starting point guard Kyle Lowry.