That’s according to Emre Sarigul, who says the midfielder’s agent has been in talks with Besiktas and Galatasaray.
Fellaini has experienced mixed fortunes since joining United from Everton in a £27.5m deal four years ago.
But he seems to have found a role for himself under Jose Mourinho, with the Portuguese often using him as an impact sub.
Fellaini is only under contract at United until the end of the season though.
And it seems he could be considering quitting the Premier League next summer.
Turkish football expert Sarigul has revealed who Fellaini’s agent has been negotiating with.
“Man United fans may (or may not) be pleased to know Fellaini’s agent has been in talks with Besiktas and Galatasaray,” he said on Twitter.
However, Sarigul suggested a switch to Istanbul might not be the only thing on Fellaini’s mind.
“Two possibilities -Fellaini’s agent is strengthening his hand for contract talks with Man Utd. He’s off to Turkey’” he added.
Sarigul’s update comes a matter of days after Besiktas official Metin Albayrak confirmed the club’s interest in Fellaini.
“Transfer plans never end, we are always working,” he said.
“Fellaini is on our list, we have made efforts to sign him but not just him.
“He is not the only player we scouted, our scouting team watched 20 games live this week.
“We are keeping tabs on several players.
“The club has plans for Turkey and Europe, there are negotiations.
“We want to make the signing for the winter transfer window or for the end of the season.”