Patrick Willis Explains Decision to Retire from NFL
San Francisco linebacker Patrick Willis announces his retirement - The Globe and Mail
Willis: Maybe it's not all that surprising - Mississippi Sports Hall of Fame
Players react to Chris Borland's retirement with surprise, respect - NBC Sports
Outpouring of love and respect as Joe Staley says goodbye to the 49ers
Patrick Willis Will Officially Retire Tuesday, 49ers Announce, News, Scores, Highlights, Stats, and Rumors
49ers linebacker Patrick Willis retiring from NFL
Patrick Willis Explains Decision to Retire from NFL
How many millions did 49ers' Chris Borland give up by retiring at 24?
Patrick Willis Explains Decision to Retire from NFL
Patrick Willis Explains Decision to Retire from NFL