Roeder said: “I saw Jose at the start of the season at a managers’ meeting in London and he said to me he was not sure he was doing the right thing letting Duffer go.
“He thought he was a great lad, and he told me that Damien could have stayed at Chelsea if he wanted to.
“Duffer was a very successful player at Chelsea. He won two Championships. But he decided it was time to move on.”
He added: “At the start of the season, it’s fair to say the Newcastle fans did not see the best of Damien Duff.
“That has now changed. We have only lost two of the last 13 games. The atmosphere at the training ground is fantastic and Damien, like many of the other players over the last six weeks, has shown the form we knew he could.
“He was doing very well at Arsenal before he damaged his cartilage, and he is now doing extra sessions in training.
“He is, like Jose has said, an ultimate professional. If all players had Damien’s attitude and application, life would be a lot easier.”