And another departee: Rookie LB for the 49ers, done because of his own head injury concerns.

This could become the biggest story of the 2015 off-season.

Yet another player cites head injuries (or at least the concern of them) as his reason for an untimely retirement.

Rookie linebacker Chris Borland is done with football, retiring from the 49ers after one season.

Was actually looking at major playing time in season two.

Outside the Lines reports that Borland took one look at the risks (that most of the worshippers say these players knew), and is out of the game as a result...

"I feel largely the same, as sharp as I've ever been, for me it's wanting to be proactive," said Borland. "I'm concerned that if you wait till you have symptoms, it's too late. ... There are a lot of unknowns. I can't claim that X will happen. I just want to live a long healthy life, and I don't want to have any neurological diseases or die younger than I would otherwise." 

Football is eventually going to go away unless people are literally forced to play.  This is why.

(Source for the quote:  Deadspin.  Hat-tip to one of my few online commenters, who pointed this one out to me.)