Manchester United will warn their top stars not to write autobiographies while at Old Trafford after the furore surrounding Roy Keane's revelations.
The United captain has been charged by the Football Association with two counts of misconduct after revealing in his autobiography how he deliberately set out to injure Manchester City's Alf Inge Haaland.
Jaap Stam's book also caused controversy when he accused manager Sir Alex Ferguson of making illegal approaches to the Dutchman while he was at PSV Eindhoven.
Stam was offloaded to Lazio shortly after and United will now clamp down on their players in a bid to avoid any further embarrassment - although David Beckham's forthcoming autobiography will go ahead as planned.
"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," managing director David Gill said.
"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.
"You can't apply rules retrospectively. If he [Beckham] has signed a contract, we're not in a position to deny him that opportunity."