Calvin Johnson reportedly follows Barry Sanders, retires

The NFL has lost yet another star to early retirement, it seems. After a few players led the way with early retirements last year, including linebacker Patrick Willis who seemed to be on a Hall of Fame trajectory, Calvin Johson is ending his career as well. ESPN's Adam Schefter reports that the Detroit Lions receiver told head coach Jim Caldwell that he was retiring, though he hasn't made it public and official yet.

Johnson is just 30 years old, and still playing at a very high level. He had 88 catches for 1,214 yards this past season, and could challenge a number of Jerry Rice's seemingly untouchable records if he continues playing for another 10 years. But instead, he's retiring having played in just two playoff games. In that, he joins Barry Sanders, another former Detroit Lion who assailed the record books and had a ridiculous amount of success before abruptly retiring.

Johnson's reported retirement not only robs the NFL of one of its best players, it also raises further existential questions about the future of the game. With increasing evidence and public awareness that concussions and even subconcussive hits that can't be legislated out of the game lead to irreversible brain damage, even some of its stars are now stepping back. The NFL still reigns supreme, but that won't necessarily always be the case -- and this may just be how the end starts.

If it is, though, it's going to take years and years for that to come to fruition. For now, Johnson's retirement just means that the NFL is losing another star.