Fellaini has struggled to impress in his three seasons at Old Trafford since joining from Everton for £27.5m.
The 28-year-old was in and out of the team under former boss Louis van Gaal and managed just four goals in all competitions last season.
But he is hoping to reboot his United fortunes following Mourinho’s appointment.
"As far as my future is concerned, I'm under contract with Manchester United,” Fellaini said.
“In addition, a great manager, Jose Mourinho, is arriving.
