Nah - that was Mourinho being Mourinho and trying to deflect pressure from his players.
He is not new to the EPL and rarely rotated his players at Chelsea e.g. in 2014, Chelsea played a total of 54 games of which 3 were meaningless games after winning the league and 5 were cup games against lower league opposition, still Hazard played 49, Ivanovic 49, Matic 46, Fabregas 45 and Cahill 45. Even Oscar with hi concussion problems still played 35.
It was same thing at Madrid. Once Mourinho settles his starting 11, he plays them every game possible to build them into a finer tuned unit. That is why Zlatan, at his old age, played almost every game till he got injured. Mourinho only makes changes when he is forced to or not satisfied with the player in the current spot. Its like what he did with Rashford and Martial as they were initially playing 50/50 but once Rashford pulled ahead, Martial was pseudo permanently on the bench.