The '4 Minutes' singer is due to play London's O2 arena tonight (04.07.09) and tomorrow (05.07.09) - the venue where Michael would have staged his comeback shows later this month - and is planning to dedicate her performances to the King of Pop.
She explained: "He was the King who inspired us all. I am so terribly sad about Michael Jackson's death. I don't know what artist wasn't inspired by him. Everybody grew up in awe of him.
"To work with him and become friends and hang out with him, was exciting for me. I used to love picking his brains about musical stuff."
Michael - who died of a suspected cardiac arrest in Los Angeles last week, aged 50 - appeared alongside his brothers Jackie, Tito, Jermaine and Marlon in the Jackson 5 from the age of seven.
Madonna insists it was Michael's early induction into the world of fame which made him so unusual.
She told Britain's The Sun newspaper: "To be able to do what he did at such an early age was unearthly.
"Obviously we have very different personalities - he was a lot more shy than I am. That's because I was allowed to have a normal childhood and he wasn't, so there was a vulnerable side to him that made you want to take care of him and protect him.
"He was a real paradox, one of the world's greatest performers and obviously very confident on stage, but in real life he was very shy and you really felt for him."
Madonna also revealed she had offered to sing with Michael - who is survived by three children, Prince Michael, 12, Paris, 11, and seven-year-old Prince Michael II - at the 50 shows he had planned in London.
She joked: "I don't know what we could have done together. I could have carried his bags for him maybe."
Now, the 50-year-old singer has decided to pay tribute to Michael during her upcoming shows.
She will play a medley of Michael's songs - including 'Billie Jean' - and has a dancer who will dress as the late pop icon and perform some of his signature dance moves.
Madonna was distraught after Michael's death was announced, admitting she had been reduced to tears.
She said at the time: "I can't stop crying over the sad news. I have always admired Michael Jackson. The world has lost one of the greats, but his music will live on forever! My heart goes out to his three children and other members of his family. God bless."
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