Duff is currently considering a £17million move to Chelsea and weekend reports were linking the Prem,ier League champions with a move for the Republic of Ireland striker after their failed attempts to take Ronaldhino to Old Trafford.
"Let's kill the Damien Duff story straight away," United chief executive Peter Kenyon said.
"There has been no approach to the club or the player and there won't be. He is due to sign for Chelsea. We are not in for him."