The Portuguese has utilised the full depth of his squad so far this term, as he continues to find his strongest XI.
Mourinho's team selections have been called into question at times, particularly over his use of midfielder Juan Mata who has been played sparingly in the Premier League.
The dilemma for the 50-year-old was heightened by Chelsea's impressive 2-0 victory at Arsenal in the League Cup on Tuesday, a game in which he made 10 changes to his side.
"It's not easy for me to leave some players at home or on the bench, because I think everybody deserves to play," he said.
"To have all these choices is a good problem. To have all the players playing well and be very much committed with the group is fantastic.
"But to be the man responsible to say you are not selected at this moment is very hard because I feel I am unfair with all of them because they are doing everything to play.
"They cannot do anything else from what they are doing. In this moment my players, all of them, they have a collective soul.
"When they have a chance to play they play a magnificent match at the Emirates, so at this moment it’s a difficult feeling for me."
Chelsea could go to the summit of the Premier League if they can beat Newcastle United in the Premier League's early fixture on Saturday, with table-toppers Arsenal due to play third-placed Liverpool in the late kick-off.
But Mourinho insists his focus is solely on securing three points.
"It's important to go in the right direction, to play the way we are playing," he added.
"The quality of our game is good, the results in the last month are fantastic because we won every match in every competition. We had to play Schalke away, Arsenal away and Man City at home, so October was very difficult for us.
"But at the moment being top is a question of one or two points and that's not important.
"We have one of the most difficult matches of the whole season at St James' Park but we want to try and keep winning."
