Former NCAA coach Bobby Knight talks on the phone during Republican presidential nominee Donald Trump's campaign roundtable with small business leaders in Altoona, Wisconsin, U.S. November 1, 2016. REUTERS/Carlo Allegri 

Republican presidential nominee Donald Trump and former NCAA basketball coach Bobby Knight appear at campaign rally in Grand Rapids, Michigan U.S. October 31, 2016. REUTERS/Carlo Allegri 

Former Indiana basketball coach Bobby Knight (R) departs after introducing Republican presidential nominee Donald Trump at a rally with supporters in Aston, Pennsylvania, U.S. September 22, 2016. REUTERS/Jonathan Ernst 

Former Indiana basketball coach Bobby Knight (L) delivers a few remarks before Republican presidential nominee Donald Trump sits down to a business roundtable at the Staub Manufacturing plant in Dayton, Ohio, U.S. September 21, 2016. REUTERS/Jonathan Ernst 

Former Indiana basketball coach Bobby Knight introduces Republican presidential nominee Donald Trump to the stage to rally with supporters in Toledo, Ohio, U.S. September 21, 2016. REUTERS/Jonathan Ernst 

Republican vice presidential nominee Mike Pence (L) introduces former basketball coach Bobby Knight (R) to welcome Donald Trump to the stage to rally with supporters in Toledo, Ohio, U.S. September 21, 2016. REUTERS/Jonathan Ernst 

Republican presidential nominee Donald Trump takes the stage after being announced by former Indiana University basketball coach Bobby Knight as he rallies with supporters in Toledo, Ohio, U.S., September 21, 2016. REUTERS/Jonathan Ernst 

U.S. Republican Presidential candidate Donald Trump introduces legendary basketball coach Bobby Knight at a campaign event in Indianapolis, Indiana, United States, April 27, 2016. REUTERS/Jim Young

U.S. Republican Presidential candidate Donald Trump embraces legendary basketball coach Bobby Knight at a campaign event in Indianapolis, Indiana, United States, April 27, 2016. REUTERS/Jim Young