I'm with Matt26, Patty Mills. More playing time, senior point guard ahead of carter and has more space to play his own game. Plus, if Nash plays Mills and his perennial team mate, Lamarcus Aldridge together, the two know each other's games intimately. You couldn't a better secondary duo.
Oh, okay. That makes sense. Though probably applies to approximately 430 of the 450 active NBA players and I doubt his move to Brooklyn changes it unfortunately! (Though it certainly wont hurt).