When it comes to professional football, not every player is able to make the transition. The majority of them don’t last more than a season or two, and every offseason every team trims down a 90-man roster down to 63, including the 53-man roster and the 10-man practice squad.
The NFL is the elite of the elite, those who execute their profession at the highest level available in the world, and we see that even sometimes that is not enough. Who could argue, for example, that there are 32 legitimate starting quarterbacks in the league right now?
The point is, however, that sometimes players only ‘make it’ part of the way into the NFL.