Chris Borland retiring due to concerns about head trauma

I don't even...holy crap. ESPN is reporting San Francisco 49ers linebacker Chris Borland is retiring from the NFL because of concerns about the long-term effects of repetitive head trauma. Outside The Lines spoke with him about this and he had several quotes:

"I just honestly want to do what's best for my health," Borland told "Outside the Lines." "From what I've researched and what I've experienced, I don't think it's worth the risk."

"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."

He had some specifics about what might have directly led to his decision:

Borland said he began to have misgivings during training camp. He said he sustained what he believed to be a concussion stuffing a running play but played through it, in part because he was trying to make the team. "I just thought to myself, 'What am I doing? Is this how I'm going to live my adult life, banging my head, especially with what I've learned and knew about the dangers?'"

I am just about speechless on this. There has been plenty of talk about the concerns of head trauma in football, and we have seen careers cut short because of head trauma, but we rarely see a player walk away in this manner. This is....wow.