United's book pledge
The Premiership giants have issued a directive stating it would be inappropriate for a player to write their life's story while they are still at Old Trafford.
Keane's explosive tome has landed him with two charges of bringing the game into disrepute from The Football Association.
The charges relate to Keane's reckless challenge on Manchester City player Alf Inge Haaland in April 2001, and the Irish firebrand faces a suspension from The FA.
In response to the furore created by Keane's autobiography, United believe it would be unwise for any future books to be published, although they confirmed they will back their skipper to the hilt.
"We need to make it clear that we don't think it's appropriate for players to publish a book while they're still playing for Manchester United," said managing director David Gill.
"We want them to concentrate on playing.
"We believe they can do other commercial deals. David Beckham's doing Castrol and Pepsi, Roy Keane does Aer Lingus, that's fine. A book is another issue."
Gill also revealed that United's lawyers did not vet the book before it hit the shops.
He added: "I'm sure obviously the publisher's lawyers looked at it, his lawyers looked at it. Manchester United, our in-house lawyers, did not look at it.
"It's going to go through the process and clearly we will support Roy as a key player within Manchester United."
However, Gill confirmed their stance would not be applicable to United midfielder Beckham, who had already agreed a deal to publish his autobiography next year.
Gill stated: "You can't apply the rules retrospectively. If he's signed a contract, we're not in a position to deny him that opportunity."