Falcao, Juan Cuadrado and Willian only came on for the last 20 minutes of Saturday’s friendly against Paris Saint-Germain, having only trained for two days beforehand.
But the trio are likely to get a more strenuous work-out in Washington on Tuesday, when Champions League winners Barcelona will provide the opposition.
Asked why he brought them off the bench in Charlotte at the weekend, Mourinho told Chelsea TV: “I discussed it a lot with Rui Faria (assistant coach) and we thought that 20 minutes of football is more rich, has more ingredients, than training in a small group of three.
“So we decided to give Falcao, Willlian and Juan Cuadrado this 20 to 25 minutes, which was very good for them.
“Now, they are not ready to start but, against Barcelona, I think they can go from 20 to 30 minutes. I will give them that.”
Chelsea eventually defeated PSG on penalties after a 1-1 draw and Mourinho thinks it was an excellent work-out ahead of the new season.
The manager was not happy with the goal conceded but felt it was a consequence of typical pre-season ‘slow thinking’.
He said: “Paris Saint-Germain’s intensity was obviously much higher than ours but, as a training session and a complement for what we are doing, it was very good for us.
“Step by step, the players have some more happiness in their legs.
“We still feel some of them have accumulation of fatigue with slow movement and slow thinking and that goal was typical – too slow to think to take the ball out of the pressure zone.
“But, step by step, we are coming.”