United triggered a one-year extension in the Belgian's contract in January, which extends the 29-year-old's stay at the club until 2017-18. Fellaini has 27 Premier League appearances to his name this season and has quickly become one of manager Jose Mourinho's favourites.
"We are focusing our efforts on signing a midfielder and striker," Usta told Takvim, via Turkish Football. "We are looking for players who will improve the team and help fill our new stadium.
"The midfielders we are in talks with are Fellaini and Natkho. We are also in talks with the striker Soldado."