A minor-league NFL would be filled with the lowest rung of potential NFL players, simply based on the potential for injuries. Not even 6th-round draft choices would be placed there. So I don't see that there would ever be a league push for such a thing.
Now I was thinking what if the NFL had a minor league. Just league to keep the young free agents in football condition and give them experience. I know there is NFL europe but what about a league during the season like maybe have the NFL and CFL join up and the CFL could be the minor league. What does everyone else think of this idea?