Fellaini can even sign a pre-contract agreement with an overseas club in January.
And Mourinho insists that the matter is out of his hands now and that it is up to the board to negotiate with the former Everton midfielder over a new deal.
"I respect both - the player because the player has the right to decide his future".
Fellaini has just over seven months left on his current United deal and is thought to have rejected the offer an extension in September after failing to agree on fresh terms.
Their want for further defensive reinforcements combined with their need to comply with Financial Fair Play requirements has led them to pursue Fellaini; the Parisians are already in discussions with Fellaini's representatives and are not anxious by the Belgian's potentially vast wage demands due to the lack of transfer fee required. He finishes his contract he has the right to decide his future.
He went on to state: "So I just wait, wishing that they will have an understanding but it's out of my control".
Patrick Beverley to miss rest of season after undergoing knee surgery
In his absence, expect rookie Sindarius Thornwell or Lou Williams to slide into the starting lineup alongside Austin Rivers . The big man is now averaging 10.5 points, 13.8 rebounds and 1.2 blocks per game on 66.1 percent shooting.
Despite the speculation, the 30-year-old is set to be involved when Brighton arrive at Old Trafford on Saturday.
"No, (Bailly is) not back", the United boss said.
"Rojo played very well".
"No, not ready (to start)", Mourinho said of Ibrahimovic. You don't play him only if the team is losing or winning.
The return of such players is important at a crucial stage of the Premier League campaign, with second-place United facing Brighton, Watford and Arsenal in quick succession.
The Red Devils trail rivals Manchester City by eight points and need to maintain a manageable gap before they play Pep Guardiola's men in early December. The Champions League finished after the Basle game, we switch off and move to the Premier League.