When Narcos: Mexico star Tenoch Huerta was first announced to have joined the cast of the Marvel Cinematic Universe sequel Black Panther: Wakanda Foreverit was basically taken for granted from the start that he was cast as Namor the Submarine, a character fans have been desperate to see in live-action for a very long time.
Since then we have been inundated with new speculation, scuttlebut and hearsay, but on an official level Huerta has only been publicly referred to as Namor on one occasion, and even then the mention has not been confirmed or denied by anyone from Marvel.
