NFL Rookie Retiring Over Brain Injury Fears SF 49er Chris Borland, 24, is leaving the NFL to avoid head trauma By Jenn Gidman, Newser Staff Posted Mar 17, 2015 7:44 AM CDT 31 comments Comments In this Dec. 8, 2012, file photo, Wisconsin linebacker Chris Borland talks during a Rose Bowl news conference in Los Angeles. (AP Photo/Nick Ut, File) (Newser) – It's a move that Dan Diamond, writing for Forbes, frames as what could be "the beginning of the beginning of the end … for the NFL's reign as the nation's most popular sport." San Francisco 49ers rookie linebacker Chris Borland yesterday told ESPN's Outside the Lines that he's retiring from football due to fears of the long-term effects of head trauma. The 24-year-old said he came to his decision after talking to family, friends, teammates, and concussion experts, making a play he ultimately believes is "best for my health." "From what I've researched and what I've experienced, I don't think it's worth the risk," he said. Borland said he's never felt better but simply wanted to take a "proactive" move to protect himself in a league where brain damage, depression, and progressive neurological issues have been linked to those who've suffered repeated head injuries while playing, ESPN notes. The 49ers issued a statement, per ESPN, that said, "While unexpected, we certainly respect Chris' decision. … We will always consider him a 49er." Borland's retirement is a particular blow to San Francisco because he was expected to replace Patrick Willis as linebacker and play a key part in the team's defense; Willis retired last week at age 30. Dozens of players reacted via Twitter, notes NBC Sports, with reactions ranging from surprise to keep calm and carry on. "No offense to anyone but I'm playing until I can't anymore. I love this game to much," tweeted Seahawks linebacker Bobby Wagner. At Forbes, Diamond notes that fan reaction was largely supportive of Borland's move and that it's "the shifting of norms" that should terrify the NFL. "When your own fans readily accept the data that your product is a killer ... at some point, the morality questions around football will be too embarrassing to ignore," he writes.