Mourinho is happy with the way his players dug deep to get the job done on the opening night of the season, while confessing that he could have done with an additional three subs.
In a dig at Premier League chief Richard Scudamore for the scheduling of the match, the Portuguese told Sky Sports News: "Mr Scudamore must be happy - it's a good way to start the Premier League. A good match. A match where I needed six changes not three.
"I want to play [Anthony] Martial but I can't, Paul Pogba can't play 90, Fred the same. I need more changes. It was not easy to manage the game from the touchline. But I told the players we had good periods, lots of glimpses of the type of football we wanted to play.
"Leicester were strong in periods but we coped with that as a team. The team played as a team. In the second half I had Andreas Pereira and Fred with a yellow card. Paul was fantastic his contribution was amazing but the fuel was disappearing.
"We were in trouble. Martial in the last 20 minutes could have given us the second goal but I couldn't make that change. The players gave everything, they gave what they had. Everybody did that."
Man United have won on the opening day in each of the last four seasons - their joint-longest run in the Premier League.