That's Tony Allen and Rudy Gay in a Grizz promo about their upgraded defense. Notice how Tony Allen coolly delivers the line "Hey, ain't that Jason Williams over there?"
That's Pacino-esque. I mean... killer delivery. I'm shocked... SHOCKED... he didn't appear in more promos for the Celtics. And by more... and mean more than the none he did.
(Thanks KWAPT)