Barcelona is looking like the only team amongst the usual big three you did mentioned that will be Left behind this season probably due to their too many crisis they are facing since the season started, they have been good until recently they started looking average with their performance but hopefully they will get back on their feet, Atletico Madrid has really been hitting hard this season trying to find their way to the top but having little hitches along the way but they can be very sure to qualify for UCL by the end of the season.
I don't know for sure how many Real Madrid players will be out through injury until January, but losing Bellingham, Camavinga and Vinicius will have a negative impact on their performance. Barcelona experienced the same case due to player injuries, but currently most of its players have recovered even though they have to find their form again after a long absence.