Per Sky Sports' Shona Duthie, Fellaini is yet to reach an agreement with the Red Devils over a new deal, and his current contract will expire at midnight on June 30.
At a press conference on Thursday, the Belgian said: "I am not worried about my contract running out, I am used to it. I am strong enough mentally to deal with it. Soon I will say where I will be playing next season. On July 1."
Football writer Jonas Giaever joked that he is eagerly awaiting his announcement:
Fellaini arrived at United under David Moyes in a £28 million deal in 2013.
Despite consistent doubts from many supporters as to whether he had the required quality to play for the Red Devils, he has made 156 appearances for the club and been frequently utilised by both of Moyes' successors, Louis van Gaal and Jose Mourinho.
What he lacks in technical ability and flair he makes up for in height and physicality, and he can be a particularly disruptive force for opponents to deal with in the final third.
If his future lies away from United they'll have lost a player that fits Mourinho's pragmatic approach, but his departure could facilitate more aesthetically pleasing play if he's replaced with a more technically adept player.