https://www.denverpost.com/2017/09/0...s-retires-nfl/
Retirement talk actually dated back to last year, two people close to Cravens said.
Defensive coordinator Joe Barry started Cravens as an inside linebacker his rookie year, believing that his athleticism would serve the team well in pass coverage against running backs and tight ends. But Cravens – undersized for the position – sustained a concussion in Week 4 and missed the next two games. Cravens returned to action in Week 7, but teammates sensed his zeal for the game – mainly playing inside linebacker – had started to wane. In Week 14, Cravens sustained a bicep injury that wound up sidelining him the final three weeks of thee season. After the second injury, Cravens didn’t report to Redskins Park for three days, and didn’t tell anyone why. After failed attempts by the coaching staff to reach him, several teammates reached out to Cravens, who informed them that he was contemplating retirement.
That response to injury wasn’t the first such instance in Cravens’ career. At one point, while playing at USC, he went missing for three days after getting hurt and considered quitting football, according to a person with knowledge of Cravens’ past.