Patrick Willis explains why he had to retire in prime of career
Patrick Willis to retire after 8 seasons with San Francisco 49ers - Niners Nation
Patrick Willis retiring from 49ers after injury-shortened season, NFL
The 5 Biggest Threats in the NFC West - Part 7 - Patrick Willis - Turf Show Times
49ers Patrick Willis Retiring
49ers Linebacker Quits After 1 Season, Citing Safety Concerns : The Two-Way : NPR
49ers linebacker Patrick Willis considering retirement at 30
Why would an NFL star retire when he can still play? Patrick Willis explains why he walked away in his prime
Patrick Willis Will Miss Rest of Season with Toe Injury, News, Scores, Highlights, Stats, and Rumors
49ers' Patrick Willis at peace with decision to retire
Chris Borland retires from 49ers after one year due to fears over head trauma, NFL
San Francisco 49ers linebacker Patrick Willis to retire