The Irish winger is back in training after a broken foot and hopes to return to first-team action in December.
Convinced a Padre Pio relic helped his father, Gerard, defy doctors who told him he had three months to live back in the 1980s, Duff Jr has more than kept the faith . . .
By playing with the same relic in his boot - and saying a daily prayer to Padre Pio.
"Someone gave him (Duff Sr) a Padre Pio relic and that's where it started," says Mary Duff in a new book on Pio that details the Irish cures attributed to him. "He made a full recovery and hasn't looked back.
"When Damien went away (to England), his father passed on the relic to him and he still has it.
"There was a time he had it in his boot or his sock when he played. We believe it helped him recover from glandular fever during his time with Blackburn Rovers."
And, to emphasise that Duff Jr remains devout, Mrs Duff adds: "When he moved from Chelsea I packed all his belongings. The rosary beads that were hanging on the kitchen press were packed with all the kitchen stuff.
"When we went to visit him in Newcastle some time later, there they were again on the kitchen press. I'm sure if people walked in they'd think, 'Oh God'. "