This weird notion that players suddenly can't play anymore once they turn 31 or 32. We signed Pirlo at 32, ffs.
It used to be true back in the day when you had players who smoked cigarettes and drank heavily, but with today's fitness levels they can play on until they're 37-38, if they really want to.
I also chuckle when I see people who're prophesizing that CR7's and Messi's performances will start to decline within the coming 5-year period. They won't. They will be absolutely killing it for at least 10 more years, both of them.
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It's also dependant on what role the player has on the field, though, I'll admit that. But even then, if a player stays fit and really wants to keep going - with today's knowledge and training methods - he can.