Having not met up to expectation in the Manchester United club I think it is hard time the French international moves to another club or maybe a new league bolster is gameplay. Is still a very good player as he has the skills and techniques to succeed at any club. I feel it just lacks enough motivation to live up to his potential.
The Italian league summer as a way of helping a player become more Sharp and clinical has was seen with Romelu Lukaku. Been just 25 years of age I believe making that move at this point will be a lifesaver for you to rejuvenate his career. At top of his career but that is in the case.
With Inter Milan in a dire need of a striker I believe Anthony martial who do recently I'm covering the void left by departed Belgium forward who left for Chelsea. Also looking at the history of English and Manchester united players moving to the Italian serie A, they always seem to do well. I don't think Martial will be an exception. I hope Inter Milan and the French striker gets what they want and meet an agreement with the club before the window closes.