Patrick Willis and Junior Seau Situations Likely Influenced Chris Borland RetirementFriends Read FreeSaveSan Francisco 49ers inside linebacker Chris Borland (50) celebrates after intercepting a pass during the first half of an NFL football game against the New York Giants in East Rutherford, N.J., Nov. 16, 2014. (AP Photo/Bill Kostroun)By Zachary Stieber3/17/2015Updated: 7/18/2015Print