Ferguson joined an outpouring of tributes to former England captain and manager Keegan, who enjoyed a stellar playing career that included spells at Scunthorpe United, Liverpool, Hamburg, Southampton and Newcastle.
In six years from 1971 to 1977 at Liverpool, he won three league titles, a European Cup, two UEFA Cups and an FA Cup.
He helped Hamburg win the Bundesliga and earned back-to-back Ballon d’Or awards in 1978 and 1979. Keegan remains one of only four English players to have won the award to date.
As a manager, he also managed Fulham and Manchester City, as well as the England national team and Newcastle.
Keegan signed Alan Shearer for a record fee of £15 million for Newcastle in 1996, and also captained England while the striker captained his country.
“He was my friend. A man everyone loved. For his passion. For his energy, but most of all for his friendship. He loved football and loved Newcastle more than anything,” Shearer said.
“I am honored to know him. We’ll miss you, Kevin.”
Current Newcastle United manager Eddie Howe contacted Keegan when he was appointed by the Magpies in 2021.
“Kevin was an inspiration to me as a young player and, I am honored to say, a friend whose guidance and support has meant a lot in recent years,” Howe said.
“He showed me incredible warmth and generosity. He had already given so much to this football club, but he immediately made me feel at home.
“Kevin understood better than anyone the privilege and responsibility of leading Newcastle United. He was always willing to share his wisdom, encouragement and support, and for that I will always be grateful.”
Former Scotland and Liverpool striker Sir Kenny Dalglish described Keegan as “one of the best players of his generation” who “wore Liverpool’s famous number seven shirt with great distinction”.
“His achievements on the pitch were exceptional, but he was also a wonderful man and a true gentleman,” added Dalglish, who was signed from Celtic to replace Keegan at Liverpool in 1977 and later also succeeded him as Newcastle manager.
“He gave a lot of people great memories and his teams played in a way that the fans loved to watch.”
“Football has lost one of its true greats.”