A disgraced rookie cop — the son of a highly respected NYPD detective — goes on trial today on charges he violently shoved a cyclist during a 2008 Critical Mass rally, then brought bogus charges against his victim.

A civilian video of then-Officer Patrick Pogan striding toward a stream of bikes near Times Square, then pushing a cyclist to the ground, became a YouTube hit.

But Pogan plans to insist that he was following his superiors’ directions, said lawyer Stuart London.