The Lisbon club's president Luis Filipe De Vieira is determined to hang on to the youngster and says there have been no offers for Fernandes.
"We have not received any official offers for our player," Vieira told A Bola. "If any offer arrives, our answer will be negative.
"Manuel is playing to a good level and he is needed for our project this season.
"No doubts exist about this question. The kid will not leave the club."