Duff has made 173 appearances in all for the west Londoners, although February's appearance off the bench in the FA Cup fourth-round exit to Sheffield United looks to have been his last for the club
A knee injury has brought this campaign to a premature end and, once recovered from surgery, he is planning to move in search of "something new" at the end of his contract.
"I'm up at the end of the season," Duff told the Irish Times
"The club haven't spoken to me and I haven't spoken to the club but we don't need to speak: I'll be leaving Fulham. I've had a great time here but that's football.
"I've had a few whispers from here and there but I'm just trying to get this [injury] right first.
"I've looked at the Australia or America thing for a bit, it would be a different way of life, a different league; I think life's too short just to be stuck in the rat race, if that's the right phrase, over here so I'd maybe like to taste something new before I go back home."
Duff would like to do a "year or two elsewhere" before plying his trade in the League of Ireland, with the winger admitting former Republic of Ireland team-mate Robbie Keane, now of LA Galaxy, has suggested a move to Major League Soccer.
"We've had a bit of banter all right," he said
"He obviously loves it and every six months I see he's signed a new deal so he'll be there for a good while yet.
"We'll see what happens but I wouldn't mind trying it to be fair but I have to get back fit first, I've got a screw in my knee now and a screw in the knee of a jinky winger doesn't really go hand in hand but we'll see what happens.
"We'd be up for it and we'd like to see the world but it wouldn't be for a jolly up. I'm still as hungry as ever."