When was the last time Martial put in a good performance? It reminds of the fans who said Anderson was the next big thing because he had a good game against Liverpool where Gerrard was in his back pocket all day long, and for years they kept holding that up as the proof of how good he can be. Never did it again though.
One game isn't proof of how good you are, consistently performing to a high level is and Martial has not done it, and doesn't look like he will do it.
If you don't perform, you don't deserve to be in the squad. Martial was up against a Premiere League debutant last week and yet came off because he was in the debutant's back pocket all game.