It seems likely that Harry Lennix’s Martian Manhunter won’t have a substantial role in Zack Snyder’s Justice League, as it seems apparent that he will be sticking to the sidelines and being vigilant. Maybe Manhunter will be acting as a harbinger of doom by the end of the movie, hence the ominous warning of war coming.
Another image from Zack Snyder’s Justice League has been uploaded by the director himself on his social media account showing a design for Cyborg only seen in very early trailers for the movie. It is accompanied by a quote from Martian Manhunter that reads, “There’s a war coming.”
As for what Lennix shot with Zack Snyder and his team, it couldn’t have been more than a minute of footage since Snyder has confirmed that he only filmed four minutes of brand-new footage.