While the Capitals forward did a little pregame warmup, moving a puck around two other pucks, the Capitals captain came by and swiped one away, ruining the entire setup.
It remains unclear whether Ovechkin was in need of a puck during warmups or just messing with his teammate, but it's probably the latter.
Between that and T.J. Oshie going around tapping everyone's rear pads, you really have to have your head on a swivel during Capitals warmups.