Martial has grown increasingly disillusioned under Jose Mourinho at Old Trafford and will seek a transfer this summer in what could prove a potential collision course.
A host of clubs have expressed an interest in signing the talented 22-year-old, including fellow Premier League side Tottenham Hotspurs.
Philippe Lamboley told French media that although United want to keep the France worldwide, they have failed to agree on a new contract with the player.
Martial's agent, Philippe Lamboley, told RMC (h/t Get French Football News) that United do not value his client based on their inability to agree a new contract: "I think that when Manchester United, the most powerful club in the world ... do not find an agreement after eight months of negotiations, it is because they do not really want to make him an important member of the squad". Anthony will speak later to discuss all of this.
I think that when Man United, who are the most powerful club, can not come to an agreement after eight months it is because they really don't want to make him a key player. This is why the decision has come.
GETTYMan Utd boss Jose Mourinho is prepared to fight to keep hold of Anthony Martial
Martial's contract expires at the end of next season so if he is dead-set on going elsewhere in the current transfer window, United will be very keen to sell in order to prevent the risk of their £36m signing leaving for nothing. "However, it is important to remember that he is under contract, Man United have the last word and we will respect the club's decision".
"We do not have the same vision of Anthony's future". Today, Anthony is disappointed because he has shown for three seasons the love he had for the club and his supporters. He brought Alexis Sanchez in January, limiting Martial's game time even further, infuriating the fans and the player alike. I can tell you that without the unconditional support of the fans, Anthony would have already asked to leave United.
"Everyone will have their opinion but I think he needs to resume his career".
Many at United are ready to block that request, but The Telegraph are reporting that Mourinho will give in to Martial's demands if he can land a high-quality replacement.
Toddlers getting too much sugar in diet
That oldest group consumed an average of 7.1 teaspoons of added sugar each day - more than the amount of sugar in a Snickers bar. However, parents should always have the goal to give their children less added sugar, say the researchers of the study.