49ers' Chris Borland retires, fearing head trauma: 'I don't think it's worth the risk' — mashable.com

Chris Borland, a linebacker for the San Francisco 49ers who has only been in the NFL for one season, has quit, citing fears about long-term effects to his health. The 24-year-old graduate of the University of Wisconsin said he notified the 49ers organization on Friday after discussing the decision, which he said was ultimately "simple," with family and medical professionals, according to ESPN's Outside the Lines.

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