Martial's agent, Philippe Lamboley, told RMC Sport that his client wanted to leave United this summer.
'There are many parameters, for now it's premature to talk about it [the reasons for his decision]. Without the unconditional support of the fans, Anthony would have already asked to leave United.
The transfer window shuts on August 9 this summer. United paid Monaco an initial £36m for his services in a deal which could eventually rise to £58m. At that point, there were comparisons with Thierry Henry, and United looked to have one of Europe's outstanding youngsters in their squad. It is important to remember that this season he scored 11 goals and gave 10 assists in five months.
Martial's future had been under up in the air for a while now.
"Today, this is not the most important question".
Mourinho doesn't exactly have the best track record with players like Martial. He was elected three times player of the month by the fans.
The forward, however, has found a starting spot hard to come by with Jose Mourinho on the bench, with 12 of his 30 league appearances in 2017-18 coming off the bench. It appears that Martial has finally given up on his Old Trafford career.
"Manchester United want to extend Anthony's contract and do not want him to leave, but we have not been able to find an agreement for several months".
The France striker's agent revealed that the player has chose to quit the club, while at the same time emphasising that the player was still under contract so agreement will need to be reached with United. I think that when Manchester United, which is the most powerful club in the world it must be remembered, does not find an agreement in eight months of negotiations, it is that it does not really want to make him an important player in the team.
The agent also insists that the decision has not been rushed, with Martial thinking through his options, but being in disagreement with Manchester United about how to go forward.
There is an argument to be made that Martial lacks the character to be a top player, but he is not the type of individual who can dip in and out of matches.
Now, despite the departure of Michael Carrick and most likely Marouane Fellaini, the imminent arrival of Brazilian midfielder Fred is unlikely to offer any more playing time to the Basque midfielder.
According to various reports on Thursday morning, Man United have no intention of selling the highly-rated Frenchman this summer.