The forward arrived at Craven Cottage during the January transfer window after a prolific spell with Olympiacos, but he struggled to make an impact in England as injuries hampered his playing time.
Mitroglou was able to make just three appearances for the London club as they tumbled out of the top flight.
Despite having signed a four-and-a-half-year contract when he arrived, it remains unclear whether the 26-year-old will look to help the club in the Championship next season.
"I do not want to talk about next season," he is quoted as saying in TheLondon Evening Standard. "I prefer to stay committed to the national team and the big summer ahead.
"It is a hug honour to play in a World Cup and I want to be committed to this feast of football."
Fulham have already begun a clear-out of some of their highest earners with Steve Sidwell, Damien Duff, John Heitinga and John Arne Riise all departing the club upon the expiration of their contracts.
