We know Jose has criticised Martial, and we know he has left him out and overlooked him in favor of others on more than a few occasions.
That is evidence he does not currently rate him, or trust him as much as others vying for the same places. But only evidence, not proof. We can only speculate on what Jose's motives are for acting as he has, but i think it is perfectly reasonable to suggest that Martial is currently not a favorite of Mourinho.
You can make the argument Jose does rate his potential and simply wants more from him, and i don't think many would contest that. Furthermore, we have almost exactly the same scenario playing out with Shaw. Been publicly criticized, and dropped in favor of others, but still rated and simply being asked to give more.
But, the difference i see between the 2 situations is that Jose doesn't appear to be looking to buy another Lb for next season, as yet. So we may speculate that Shaw (as it stands) will get another decent chance to prove himself next season. Whereas Jose has deemed it necessary to target Perisic, for a large enough fee to suggest he is a starter, and who will likely play in Martial's preferred position next season.
Now i want Martial to be a success here as much as anyone, but i have concerns for him next season. Martial struggled last season, and there wasn't even really a stand out contender putting pressure on his place. Yet now we have specifically targeted Perisic for that position, i am struggling to see when Martial is going to get the opportunities needed to build his confidence and improve. Mourinho just doesn't piss about, if you give him what he asks for you are in, if you don't, you lose both his trust and your place.