Barton is currently enjoying his loan spell at Marseille, but was quick to criticise his former team-mates following the Hoop's relegation on Sunday afternoon, describing some members of the squad as "maggots" shortly after the team's 0-0 draw at Reading.
The 30-year-old revealed it would be tough to leave the French club but Fernandes said on QPR Player: "Marseille have got to put an offer in. Joey is under contract and Joey would be a very useful player for Queens Park Rangers."
He added: "He helped Newcastle out (of the Championship). Some would say we lacked his fighting spirit in the midfield.
"But if Joey and Marseille want (the transfer), then we will talk. However, he is a QPR player, and is contracted to QPR.
"That has to be a financial deal which would have to be worked out if he wants to go to Marseille, but as far as I am concerned he is a QPR player and in the summer will come back."
Harry Redknapp is set to remain in charge next season, despite failing to guide the club to safety after taking over from Mark Hughes last November.
The former Tottenham manager brought in the likes of striker Loic Remy and defender Christopher Samba on big-money transfers during the January window.
While both players are probably unlikely to be part of the Hoops' fight to regain their top-flight status, Fernandes remains optimistic the west London club will have a squad capable of mounting a sustained promotion challenge.
"We have been through it. There are many players we want to keep, some players we think don't want to stay and some players who are going to move on, but it is not insurmountable," the Malaysian businessman said. "I am a positive person. People would say I am not realistic, but if you go through player by player, we will sort them out."
- Sports & Recreation