Besides Danny Ainge being attached at the hip to Marcus Smart, Danny just loves that type of player. The every-rebound-and-loose-ball-is-mine attitude. Marcus Morris has some of that in him, too, and that is why the Marci are in the starting unit, and the Celtics have gone on a run.
Smart and Morris were part of the Bench With Attitude in the early going of a less-than-expected season. When their attitude was transferred to the starting unit, things turned around in a positive way very quickly.