The incident accelerated the deterioration of the pair's relationship that ended with Beckham's departure to Real Madrid this summer.
At the time both played down the incident, although privately the Beckham camp was angry that Ferguson had not apologised publicly.
Beckham said: "I want to assure all United fans that there is complete harmony and focus as we prepare for the Juventus game. The dressing-room incident was just one of those things - it's all in the past now."
Ferguson added: "Contrary to reports, David didn't have two stitches. He had none. It was a graze and it was dealt with through the doctor at the time.
"It was an incident that was freakish. If I tried it a million times, it could not happen again. If it could, I would have carried on playing."
Rumours the book will reveal Ferguson threw the boot at Beckham deliberately appear unfounded.
United are said to be relaxed about potential revelations after senior officials were briefed on the key passages.
Those of most concern surround the boot incident and Beckham's departure, but United are only likely to respond if they believe there are any factual inaccuracies, especially over his move to Madrid.
United insist they only decided to sell Beckham when it became clear he would not enter into new contract talks and that his advisers had already met Real about a move.
After Jaap Stam told how United had made an illegal approach to sign him in his book, the club then brought in a rule that all books by employees had to be approved by them.
But Beckham's deal was already signed and now he is no longer their player that is irrelevant.
