We are already learning that fewer kids are playing football in high school, and that down the road we aren’t going to produce enough high-quality players, and therefore universities and the NFL will look more and more to foreign-born players, and set up “factories” in places like Africa.
I say in 20 years, more than half of football players will be foreigners.
Not sure that will happen. Although a number of kickers from Australia are showing up on US teams, football remains a uniquely American sport, and most people outside the US wouldn't know a quarterback from a cornerback.