Rojo has 18 months left on his current contract and the Red Devils are prepared to use him as a makeweight as a result.
Fernandes has been in stunning form for Sporting this season, netting 15 goals and providing 13 assists in all competitions.
Sporting manager Silas has admitted the club is looking at potential replacements in case Fernandes leaves imminently.
He said: “I can’t guarantee any of these things because I don’t know. Bruno is a huge player and all players like him have a lot of market.