The family of Bill McCartney says the former Colorado football coaching great was recently diagnosed with late-onset dementia and Alzheimer's.
Family members said in a statement that McCartney is ''still the same Coach Mac - biking, golfing, supporting the Buffs and being an active member of his church.''
Therefore, the statement continued, ''We are making this public to ask for your understanding and patience as we know he frequently runs into fans, friends and former players. This is a frustrating and confusing disease, and if he appears disconnected or unknowing, please don't take it personally.''
McCartney, who turns 76 later this month, led the Buffaloes to their only national championship in 1990. He's the winningest coach in Colorado history at 93-55-5 and he was inducted into the College Football Hall of Fame in 2013.
Another member of that exclusive club is former Colorado star defender Alfred Williams, who played on that national championship team and later won two Super Bowl rings with the Denver Broncos.
Now a radio broadcaster, Williams said that McCartney's illness was no secret to ''the Colorado football family,'' which has known about the situation for a couple of years. He said McCartney has told him of his short-term memory troubles in the past.
''But when it was reported today, it was also reported that it was getting worse. And I think that is a surprise to all of us because Mac has always been the strongest and most fit man that we've known,'' Williams said.
Following his retirement from coaching, McCartney went to work full-time for Promise Keepers, a Christian organization he helped to create in 1990, to help enrich men's lives. He remains active in its mission today.
McCartney's outspoken beliefs about religion and on social issues made him a lightning rod for critics during his coaching career in Boulder.
''Coach Mac is a unique character in American history because I don't believe that you're going to find anybody that knows him that will agree with everything that he says. Yet, you'll still have respect for him,'' Williams said.
Williams said the only drill McCartney ran himself at CU was punt return because he felt it was so important.
''So, every day he'd walk out with a yardstick and he would just stand there during the punt team practice and he would just say, `Stop!' Everybody had to stop at once and then would just lay down the stick. If you were off by an inch, an inch and a-half, or a quarter-inch, he'd reset you. It was just great,'' Williams said.
''And everybody knew he was serious about football. But he was more serious about his family and how the players were treated. He was a champion for every athlete at the University of Colorado.
''I just love the man,'' Williams added. ''I don't feel sorry for him, and I don't think that he would want that. If you talk to him, he'd just tell you that this is just the next fight. This is the next game. This is the next opportunity to pull through.''