I stumbled upon this awesome illustration of football in deep space by the King of Comics himself, Jack Kirby, and couldn't believe it was once commissioned by the same league now professionally sanitized by Roger Goodell. The double page spread above apparently appeared in the October 22, 1973 issue of Pro Magazine, the NFL's official publication at the time. You can view more awesome work Kirby did for Pro here.
Sports and comic fans alike love to speculate which superheroes would dominate which sports, but drafting an NFL team just of Kirby characters adds a new wrinkle to the question. I'd like to see what Mr. Miracle could do in the open field.