Antonio Brown has seen enough of Matt Canada's offense in Pittsburgh -- the controversial ex-NFL superstar just unloaded on the Steelers coach in a social media rant ... wildly comparing him to Adolf Hitler.
AB has been an outspoken critic of Canada recently ... ripping his former team over its scoring struggles this season, and even throwing out his interest in replacing the current offensive coordinator.
Brown continued his public bashing on Monday ... sharing a picture of Canada with Hitler's signature toothbrush mustache drawn on it and saying, "Adolf Canada.