The Republic of Ireland international has missed the last two months with a knee injury, having started just nine Premier League games before the problem occurred.
And the 35-year-old has revealed that he has no interest in discussing new terms with the Craven Cottage club.
"I'm up at the end of the season," he 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 (his knee) 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's international team-mate Robbie Keane currently plies his trade in the MLS for Los Angeles Galaxy, and Duff said he would consider a move to the United States.
"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."
