Dragons boss Vitor Pereira is currently satisfied with his options in the centre of the park, but with both Joao Moutinho and Fernando nearing the exit door, the talented coach might need to act in the January transfer window.
A Bola understands that FC Porto have already opened talks with Sporting Lisbon over midfielder Marat Izmailov.
Izmailov, 30, has always been regarded a very important player at Estadio Joao Alvalade, but numerous injuries prevented him from fulfilling his potential.
Porto have been following the attacking midfielder for a while now, and they believe this is the right time to step up their interest.
Sporting Lisbon chiefs are open to a possibility of cashing in on their star player, but lengthy negotiations appear on the cards.
Marat Izmailov, under contract until June 2015, has made just 81 Primeira Liga appearances for the Lions, scoring 13 goals in the process.