How former San Francisco 49ers Chris Borland's retirement could
Chris Borland Retires from 49ers: Twitter Reacts to LB Retiring
Ex-49er Chris Borland still asked why he quit — and he keeps
49ers linebacker Chris Borland retiring at 24 due to long-term
San Francisco 49ers Chris Borland retires over repeated head
[node:title] San Francisco 49ers Rookie Chris Borland Retires at 24
San Francisco 49ers Chris Borland retires over repeated head
Report: Jets LT Ferguson to retire
San Francisco 49ers rookie LB Chris Borland retires at age 24 over
Chris Borland Retires from NFL at Age 24: Latest Details, Comments
49ers LB Chris Borland won't be last to retire early for safety
Ex-49er Chris Borland still asked why he quit — and he keeps
Chris Borland Retires at Age 24 Over Concussions