Disease Society led to him meeting his childhood hero Muhammad Ali. He was also invited to do some coaching at Sunderland in the 1986–87 season by manager Lawrie McMenemy, and worked as a part-time coach from February to April 1987, at which point he was promoted to first-team coach. His wife, Jennifer, left him in October 1987 after he punched her in the face and kicked her down the stairs of the family home; this ended a difficult 15-year marriage blighted by frequent infidelity on his part. They had two children: Cara (born July 1976) and Dale (born January 1981). Former Liverpool teammate Ray Clemence recalled how Kennedy "worked hard and played hard". Other teammates Steve Heighway and Phil Thompson noted that Kennedy was a "quiet man", though "women were always chasing after him" and "off the pitch he needed to be handled quite gently, and everything had to be organised just right otherwise there would be trouble". Completing a bad end to 1987, his licence at the Melton Constable was revoked. His prescribed L-DOPA medication also became less effective and he became increasingly isolated. His condition improved when he began injections of apomorphine. He was reliant on the Professional Footballers' Association to pay his medical expenses, and his divorce as well as business and tax problems wiped out his savings. A testimonial game was held between Arsenal and Liverpool in April 1991. A charity appeal was also set up to help pay his living costs. In late 1992 he began suffering from extreme paranoia, mostly due to the side effects of his medication, but regained his mental faculties following a short stay in hospital. He published his autobiography Ray of Hope in 1993, co-authored by Dr. Andrew Lees, who at that time treated Kennedy for Parkinson's disease. Later that year he sold his collection of medals and international caps to raise funds. In 2002, he was reported as living alone in a bungalow in New Hartley. In an interview two years later, he said that he suffered from loneliness and hallucinations due to his condition and the side effects of his medication. Following the interview a Liverpool fan bought Kennedy a computer, which allowed him to make friends on football chat rooms. Kennedy remained a favourite amongst Liverpool supporters decades after leaving the club, and was voted in at No. 25 on the 2013 poll '100 Players Who Shook