Mourinho left Bale out of the squad for their FA Cup defeat at Everton in midweek.
The Portuguese coach claimed Bale was missing because of an injury but the player had posted a message hours earlier, in which he intimated he was ready to play.
Speaking ahead of Saturday’s match against City, Mourinho said: “Probably the post was not even his responsibility, but it was showing that the training session was great and I’m ready which was totally wrong. So when questioned I had to give the reality of things.
“I repeat for the last time. He was not feeling good. He asked for a scan. He had a scan.
“The scan did not show an injury but his feelings were still there but as coaches, medical people we can never go against the player’s feelings.”