Speaking at a press conference after unveiling his new book, My Autobiography, Ferguson branded the former Italian international "an outstanding player".
"Maldini was an outstanding player. I loved him. I approached his father once, Cesare, and the look he gave me I knew never to go back to him. He was never leaving Milan," he told reporters.
Maldini, now 45, spent 24 years in the first team at Milan.