Chelsea boss Jose Mourinho has spoken to Damien Duff about the possibility of the winger leaving Stamford Bridge.
Duff was a £17m signing from Blackburn in July 2003
The 27-year-old Republic of Ireland international is thought to be close to a move to Tottenham.
Mourinho said: "In my squad there are always a few I want to leave and a lot of players I'm desperate to keep.
"And there are always a couple of players I'd like to keep but I have no courage to keep when I can't promise they'll be playing 75% of the matches."
Mourinho added: "I like Damien as a player and as a person. I listened to him for a couple of hours and I could understand what he has in his mind.
Ashley Cole is a good player but we've been connected with every left-back in Europe
"After that it becomes business. He's such a good player we will do good business with another club."
Mourinho has already revealed he will make at least one more signing this summer.
That player is likely to be a replacement for left-back Asier del Horno, who is close to a return to Spain, but Mourinho would not say if Arsenal left-back Ashley Cole was a potential target.
"Ashley is an Arsenal player so I'm not going to say anything. We have Wayne Bridge back from Fulham and he is a player that we trust," he said.
"We will see what happens with Asier del Horno and if we sell him there will be space to buy a new player.
"Ashley Cole is a good player but we've been connected with every left-back in Europe."