Will Keane and Andreas Pereira scored in a 2-0 victory at the DW Stadium today as Mourinho fielded 22 different players and rested his players who were at Euro 2016.
The Portuguese manager told MUTV afterwards that seeing such support for the team at such a low-key game motivates him to make them happy.
“I’m very happy, the result obviously is not the most important thing but it is always important,” he said. “Best of all was something that I never had before which was a friendly match, which I could call a training session against opposition, and I never saw something like this … so many supporters.
“They gave permanent support to the team, the manifestation of happiness about a few things they could see in the team, which was absolutely fantastic.
“If it is like this in a friendly match, like I said in my presentation, I will try to give them everything and I'm sure they will continue to give amazing support to the team.”
United fans are yet to see marquee signing Zlatan Ibrahimovic in a red shirt, but Mourinho was happy with the displays of other new signings Eric Bailly and Henrikh Mkhitaryan.
“Mkhitaryan is a top-class player and currently at the best stage for a footballer - 27/28 years old,” said Mourinho. “He is magnificent the way he thinks about football, he thinks very quickly and it's so sweet how he touches the ball. He can play in different positions behind the striker. He doesn't have the sharpness yet but his performance was very positive.
"With Eric, the way the fans showed how much they liked his performance when I changed him is enough. Of course he is a very young boy coming from a very different environment, but you could see what he is at this moment. I will give him everything to try to make him better and better like I did with other central defenders I've had in my hands. He has showed the potential we saw when we decided to buy him.”