Job security in professional sports is an oxymoron. It’s more like job insecurity. Athletes look over their shoulders so much that their heads should be able to spin 360 degrees, as in “The Exorcist.”
With the exception of a few franchise players — the Tom Bradys, Kobe Bryants, and Derek Jeters — employers are always on the lookout for someone better, younger, or cheaper, or all of the above.

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Again, with no reservations or pretense, you put the cart before the horse. (I purposefully employed a cliche in your honor). You stated that the Patriots win because of great players. Only 180 deegrees off point.
They win because they have a collection of players, some just above average, some good, some great, some historic,.... all of them made better ( as Tom Brady says constantly and now almost defiantly to the Blues Brothers on morning radio, who try to diminish the unparaleled acomplishments of the head coach/general manager every day), all better because they are coached, molded and led by Bill Belichick, whom you conveniently failed to mention as a reason for the team's success and, by doing so, insulting your reading audience, who make the paper possible, not always passable, but possible. Isn't it a bit embarrasing, Chris, to be so transparent in your dislike for Bill over the way he gives out information that, in doing so, you discredit yourself as a serious journalist?
The issue is that this becomes a problem when it comes to concussions. They are difficult to diagnose and players will try to fool their doctors in order to stay on the field.