Martial's agent Philippe Lamboley confirmed to French outlet RMC that his client had chose to leave United after a hard couple of seasons working with manager Jose Mourinho, as he has become a regular bench warmer and struggled to make his mark when chances came his way.
Before United's 3-2 win over Premier League champions-elect Manchester City in April, Charlotte Duncker of the Manchester Evening News reported Mourinho sent a message to Martial by dropping him for a league encounter with Swansea City.
"After thinking about all the possibilities and parameters, Anthony wants to leave Manchester United", Martial's agent told RMC Sport.
"It's important to remember that he is under contract and that Manchester United will have the last word", Lamboley added. It is a well-considered decision.
"However, we do not have the same vision on Anthony's future. Besides, I can tell you that without the unconditional support of the fans, Anthony would have already asked to leave United".
"I think when United, the most powerful club in the world, is not in agreement in eight months of negotiations, it's that they don't really want to make him an important player in the team".
'He loves the club and the fans, he showed it for three years.
"But he got hooked and showed great professionalism and was successful".
'It is important to remember that this season he scored 11 goals and gave ten assists in five months. Then came the January transfer window. Everyone will have their opinion, I think we need to resume his career.
"The only thing that I can say is that lots of managers like him and several clubs want to offer their projects to Anthony". "Anthony just wants to play, to feel happy and connect with his coach, that is essential".