The midfielder returned on Monday and, although he has not featured in any pre-season friendlies, he was thrust straight back into the action four days later as the Premier League got under way once again at Old Trafford, United winning 2-1 on Friday.
However, United saw out the rest of second-half stoppage time to start the season with three points and maintain Mourinho's unbeaten record in Premier League openers with nine wins and one draw over 10 matches.
"Even if I forget the goal, it was a complete performance", said Mourinho of the left-back's display. That being said, the majority of pundits thought David de Gea should fill the vacancy, but alas Mourinho favored more of a "position player" in the captain's role.
There was a fantastic atmosphere inside the ground because United were playing the kind of football their fans want to see and showing them something they had not seen for a long time, which was a bit of a spark. I think one defensive mistake and probably the linesman could help him and give a free-kick against Leicester.
"I think football is changing and managers should be called head coaches".
"I know it's a great cup, it will stay in my mind, but I want to win all the trophies".
People who are accustomed to watching Manchester United in recent seasons would not have been surprised by this, but that didn't stop Martial letting it be known exactly how he felt about it.
"He's in the group of players who didn't have a preseason, it's as simple as that".
Luke Shaw was the scorer, netting after an initial poor touch, with what was his first-ever goal in senior football.
Mourinho has been critical of Shaw in the past but he was full of praise for him afterwards, and rightly so.
Jose Mourinho says he should be described as Manchester United's "head coach" rather than manager, his discontent with his club's transfer business still obvious after victory over Leicester. "We had chances to score in the first half. Maybe on the next game I leave it to Alexis", said Pogba.
Dion Dublin was speaking to BBC Sport's Chris Bevan.