Mourinho made minimal changes in the opening three weeks of the Premier League campaign, with a number of players forced to watch from the sidelines as the Red Devils enjoyed a 100% start to the new season.
United will play seven times in September across three separate competitions, however, and Mourinho has talked up the importance of having a strong squad ahead of this weekend's trip to Stoke City.
"The squad is strong. The players are ready to play, the decision to leave people on the bench is hard, the decision to leave people at home is hard. The fact that now we play every three days, in relation to that, I think is good because the players will feel now that they are all involved," Mourinho told reporters.
"I think, by the end of September every player [will have] played, every player [will have] started matches because it's the normal movement of the squad and that is not a problem at all - that makes my control of my human resources better, easier and simple. But the matches are difficult and we have always the risk of being unable to keep a winning run, which is really difficult to do."
United will open their Champions League group-stage campaign at home to Basel on Tuesday night.