The French striker will be hoping to win over Mourinho as he bids to hold down a regular spot in the first team next term.
Martial has been touted as a possible transfer target for Inter Milan and it has been suggested that he could move to the Italian club on loan as part of a deal to bring Ivan Perisic to Manchester United this summer.
The striker notched up an assist for Juan Mata as Manchester United secured a 2-1 win over Sampdoria in their most recent pre-season friendly in Dublin on Wednesday night.
And speaking at his post-match news conference after the game, Mourinho insisted that he is expecting Martial to stay at the club.
Mourinho said: “Everybody is in the plan.
“The plan is to have a good squad, not just a good team. [We need] options because we have important players injured for a long time.
“They will be back by the end of the year so our squad is not so big and we need options. We need different players. Lukaku, Martial, Rashford – they are all different players and we need everybody.
“It’s going to be good, to be funny, to choose the team for every match according to the plan or the opponent. So the squad is good.”
Manchester United will kick off their Premier League campaign with a home clash against West Ham United on the opening weekend of the season later this month.
But the Red Devils will take on Real Madrid in the Uefa Super Cup in Macedonia on Tuesday before that as they look to win a trophy.
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