The game of Association Football as we know it was born in Britain at around the same time as the Industrial Revolution. Just as in every other sphere of life since the mid-19th century, the irrepressible momentum of progress in football has increased at an exponential rate ever since.
Even going back as short a period as 20 years ago, to the start of the Premier League era, there have been huge changes. There were many players and footballing styles back then that simply wouldn't succeed in this age of fitter, faster and stronger athletes and well-staffed teams of coaches and analysts.
This list is full of players who plied their trade in an age where talent was not necessarily a prerequisite, and others who may not have been greats but somehow managed to carve out careers despite an unusual hindrance of one sort or another.
It also contains some of the great names of the past, players who are indisputably held up as paragons of footballing excellence. Their presence here is not to suggest that they are somehow overrated or not worthy of such adoration, just that they would struggle to adapt to the game as it is in 2012 for a particular reason. This is not about slaughtering sacred cows, merely showing how much the game is changing at an ever increasing rate.
With that in mind, here are 12 players who wouldn't make it in today's game. Please feel free to add your own below, giving your reasons too.