https://www.espn.com/nfl/story/_/id/28486171/panthers-lb-luke-kuechly-announces-retirement-28
Dude was a heck of a player, but the game definitely took it's toll on him. As a 'Phin fan, he will be known as the guy who went just after Tannehill in the '12 draft - I recall a number of people saying he should have been the pick even.